Gravelord Lych

"Gravelord Lych drains buffs from your Monkeys, healing itself in the process. When each skull on its health bar is reached, Lych goes ethereal, resurrecting the empty shells of recently popped MOAB class Bloons. When ethereal, Lych cannot be damaged until all resurrected Bloons have been popped, including the life-draining Lych-soul Bloon. Resurrected MOAB class Bloons do not spawn children, selling towers will heal Lych."

- BTD6 Description

Gravelord Lych is a Boss Bloon added Bloons TD 6 in the 28.0 update. It is the second Boss Bloon to be introduced to Bloons TD 6, and the first Boss Bloon unique to the BTD6 Generation. Its unique properties center around resurrecting p MOAB-Class Bloons and regainingn health upon the use of transient tower buffs, selling, and sacrificing towers.

Playing Lych
Lych can be found in Boss Bloon Events, which requires a minimum of Rank 20 to access, like other events. If Lych is the boss selected for that week, then from Saturday 8:00 PM NZT to the next Thursday 4:00 PM NZT, the Boss Bloon icon will appear on the main menu screen. In some cases however, the event may end earlier than normal. Click the button to access the Boss Event page. At first the Normal Lych will be unlocked. Defeating all five tiers of Normal Lych will unlock the Elite Version.

Visual Description
Lych is a large MOAB class bloon with diamond shaped hull similar to ZOMG, is much bigger than the previous boss, Bloonarius. Lych has small propeller with multiple blades forming a cone shape, black pointy fence rods protruding from its backside. It has holes that leak out cyan-green mist, as well as lime green eyes and smaller hole in middle, it also has stitches strewn across its frontside. Purple shark-like fins protrude from its hull. Later tiers include fence tips at frontside.

Elite
Lych now has a more spooky appearance, the most noticeable visual feature being its chain censer attachment and third eye on forehead. Has more stitches, and holes for Souls to escape, it has twin set of fins on its body, the ones on its sides have jagged bat-like appearance. Later tiers include second set of tail fins, and lime green chains surrounding it and Tier 5 changing the censer with a golden one with spikes.

Lych appears into the map, being sewn together in a ghost-like fashion. Lych dies in an interesting manner, disappearing in a purple-like explosion, leaving behind what looks like a few souls.

Properties
Gravelord Lych always spawns at the location marked by a bunch of blue gravestones, around 1/50 of the track length into the track. Where there are multiple lanes on a map (e.g. Encrypted, Bazaar), Lych chooses the first available path. If there is a blimp-only lane available (e.g. Quiet Street, Cargo, Workshop), Lych will guarantee to spawn from that lane. On the map, Bloonarius Prime, Lych will take a special path that integrates both lanes (at least predicted for Lych...).

Lych is noticeably faster than Bloonarius, over twice as fast in its final Tier 5 Elite form in comparison to the Tier 5 Elite Bloonarius. Exact statistics in comparison to a red bloon are listed below:

For comparison, ZOMGs and BADs move at 18% the speed of a Red Bloon, ignoring speed ramping. Elite Tier 5 Lych, which moves the fastest of the Lych tiers, moves at 34.79% the speed of a Round 120 ZOMG (R120 ZOMGs move +98% faster than a pre-R81 ZOMG).

In addition, during Lych events, more MOABs appear than normal in earlier rounds along with rounds 40, 60, 80, and 100 also being modified. The normal bloon spawns on Round 41-48 are modified on top of each Boss Bloon spawn round and normal Round 41-48. Round modifiers are listed below:

Properties
Lych will absorb buffs from nearby towers, healing itself in the process. Selling towers also heals it. Applied and temporary buffs as well as Permanent Brew count as buffs, including charge-related abilities such as Super Monkey Fan Club, Elite Defender's life-loss trigger, and Call To Arms. However, permanent passive buffs (auras), like Jungle Drums, Shinobi Tactics, and Elite Sniper, do not give HP.

Every time Lych leeches out benefits from buffs, it will also stun nearby towers with the stolen buff for up 5 seconds regardless if it's inflicted by Elite Lych or Normal Lych. Lych regenerates 1% of its HP per highest tier of each sold or sacrificed tower (ex. a tier 5 tower regenerates 5% HP regardless of crosspaths) and 2% of its HP per stolen buff. Elite Lych regenerates twice as much health from stealing buffs.

Lych also becomes invulnerable to damage while reaching skull health. When Lych does so, it will produce a miniature soul of itself, Lych-Soul, as well as chained resurrections of any MOAB-Class Bloons that were popped in the last 20 seconds. The Lych-Soul will drain a certain amount of lives every 4 seconds; the number of lives drained depends on the tier and is much higher for the Elite version, and Lych-Soul can drop lives down to 0. The chained MOAB-Class Bloons have much more health than normal but spawn no children when destroyed. Lych remains invulnerable until the Lych-Soul and all of the resurrected MOAB-Class Bloons are popped.

An important note is that Lych cannot active its buff-sucking while invulnerable, so appliable and/or temporary buffs can be done without repercussions. Also, Lych's buff-sucking has 100 range (to test this range quantity, use a Bloon Trap on Sandbox), making it possible to get away with using those buffs.

Lych also regularly summons MOAB-class bloons from the entrance, causing rounds especially in the earliest Lych tiers to contain more MOAB-class bloons than normal.

Immunities
If at skull health, it will stay invulnerable until its resurrected offspring are all killed. It will also spawn a mini ghost version of itself, the Lych-Soul, that slowly drains lives (quantity of lives removed depends on tier and if it's normal/elite). The lives that it drains are used to heal Lych, and leaking it will result in an immediate loss. The Lych-Soul is quite fast and durable. During Lych's invulnerable phase, Lych will slow down to Bloonarius' speed.

Otherwise, Gravelord Lych's immunities are the same as other Boss Bloons:


 * Gravelord Lych has the same immunities as the BAD (Stuns, Slowness, Knockback & Instapops).
 * Immune to all forms of percentage-based damage and instant health reduction (i.e. MOAB Hex, Big Bloon Sabotage, and Grand Saboteur ability).
 * Immune to Legend of the Night's passive black hole ability
 * Immune to Navarch of the Seas hook ability

Health
This stats are for for normal Lych. For information about Elite Lych, see.

Bloon Swarms
Lych will send Lych-Soul and a number of childrenless MOAB-class bloons upon reaching skull health.

These stats are for normal Lych. For information about Elite Lych, see.

For further information about specific blimp health, refer to Resurrected Blimps.

Drained Lives
Lych's Lych-Soul absorbs a certain number of lives for every 4 seconds it exists on the screen. How many lives it drains depends on its tier.

Elite Lych
Elite Lych is a stronger version of the boss, has much more health, acts more aggressively at stealing buffs, resurrects blimps with higher health and speed, and possesses more skull health stages than its non-Elite counterpart. Popping it will give greater prizes.

Gimmick (Elite)
Values for its health regeneration gimmicks are doubled. In addition, Elite Lych-Soul spawned from Lych reaching Skull Health will drain more lives per 4 seconds.

Every time Elite Lych leeches out benefits from buffs, it will also stun nearby towers with the stolen buff for up to 5 seconds if inflicted by Elite Lych. Elite Lych also regenerates a specific percentage of HP from sapping of any kind. Generates 4% HP per stolen buff, while the formula for healing from selling or sacrificing towers remains the same at 1% HP per max tier.

Bloon Swarms
Lych will send Lych-Soul and a number of childrenless MOAB-class bloons upon reaching skull health.

For further information about specific blimp health, refer to Resurrected Blimps.

Elite Drained Lives
Elite Lych's Lych-Soul drains far more lives each time than the Normal Lych-Soul.

Healing Triggers
Lych triggers health regeneration whenever it detects a target-related tower buff or certain self-buffs. In general, any applied buffs and/or temporary buffs (e.g. Alch buffs including Permanent Brew, Overclock and Ultraboost abilities, Ultraboost permastacks) are sappable, but permanent influence buffs (e.g. Village except its abilities, Shinobi Tactics, Support Sun Temples) are not. All hero buffs are also unable to be sapped at all.

Lych regenerates 2% of its health per sapped buff, or 4% per sapped buff if Elite. Selling or sacrificing also triggers Lych, regenerating at a rate of 1% health per sold tower's max tier for both Normal and Elite, regardless of monetary value.

Below is a list of which buffs can be absorbed by Lych, and which buffs cannot:


 * This table is incomplete. You can help by expanding it. Use talk page to gather more info on what buffs are and aren't sappable.

Rewards
Gravelord Lych and its Elite variant have 5 tiers each. Popping each tier rewards Monkey Money, and additional rewards upon beating higher tiers. Starting from Tier 3, Trophies can be earned. Beating the Tier 5 boss automatically wins the game, provided the player finishes the current round, and rewards the highest tier prize plus a special badge. Beating normal Tier 5 Lych during the current event rewards the standard Lych badge, while beating Tier 5 Elite Lych after beating the current standard Lych will additionally reward an Elite Lych badge.

Refer to Boss Bloon Event/BTD6 for further details.

Summary
Lych is very elusive and exploits buff-oriented defenses by leeching at their attacking power. Lych becomes untargetable every time it reaches skull health, spawning a few childrenless MOAB-class bloons and a Lych-Soul that drains player lives. In addition to farming early in the game aggressively, try raw damaging Lych while avoiding any action that causes health-leeching to trigger, especially Alch buffs.

Lych is much faster than Bloonarius, and compensates its lower health with strong resurrected MOAB-class bloons and ability to become completely invulnerable when triggered. It also sabotages the defense by making it harder to utilize Tower Buffs as well as continually draining lives by spawning Lych-Soul whenever the player triggers Skull Health.

Tips

 * Not all buffs will feed Lych. Only non-hero, non-power buffs classified as Charge (self-buffs included, namely those from Special Abilities) are subject to absorption. Influence  buffs are totally safe.
 * Therefore, don't invest too much in buffs that can be absorbed. Alch buffs are not recommended for Lych battles, as Lych preys on all of them, even Permanent Brew. However, Overclock (but not Ultraboost) is still useful to increase income from high tier Banana Farms and packing more farms into a Monkeyopolis when Lych is not present.
 * Homeland Defense is one of the most ultimately detrimental Charge buffs to use in Lych battles, as it applies to every single applicable tower on the screen globally.
 * If planning to relocate a tower without selling during a Lych battle, use a Support Chinook or Special Poperations Heli Pilot.
 * As Lych cannot overheal itself, if you must sell a tower, do so early in the battle when its health is still close to full.
 * The most efficient way to beat the lower tiers is to use Sticky Bomb, as it deals high damage to both Lych and the spawned Lych-Soul.
 * When it comes to Powers, if ever necessary, invest in money-related powers such as Cash Drop and Thrive to scale up income quicker. It is also worth adding Banana Farmer and Tech Bot for convenience. Note that Lych cannot absorb buffs from Powers, making Monkey Boost work well against Lych.
 * Time Stop is extremely beneficial if there are Paragons in the battle, as they are the only entities unaffected by the power. Bear in mind that this also affects the lower class bloons, which may keep Lych in ethereal longer than expected if they are in an area where pops are being focused for the boss itself.
 * Mana Shield can tank lives drained by Lych-Soul, surprisingly, which comes especially handy in the lower-tiers due to the more reliable life-generating upgrades being locked away into rather expensive upgrades without getting Marketplaces with Healthy Bananas.
 * Lych during its idle phase moves about twice as fast as Bloonarius. On moderate length maps, it can reach halfway the map's track by around Round 45-46, compared to around Round 50 with Bloonarius.

Video Guides
Ranked Lych Normal



Ranked Lych Elite



Bugs

 * Current
 * [28.0] Sometimes you can Crash the game by leaving and entering Lych level way too fast.
 * [28.0] Legend of the night's shield ability will work against lych's summons but doing so will cause lych to be immune to damage until you leave and re-enter the game.
 * [28.0] Exiting and re-entering after Lych spawns its reanimated blimps will cause it to not reanimate blimps the second time around provided the round doesn't increase and it's not the initial round Lych spawns on. This can be a potential life-saver for early tiers as its early reanimated blimps are a big threat.


 * Patched


 * [28.0] Exiting and Re-entering the level while Lych battle is on will not resume rounds untill you press play. This will leave lych fighting alone with the monkeys without capability of resurrecting any bloons, making the entire battle much easier. Patched in 28.2; going back to a game save while the boss is active will now automatically start the round while the boss continues to move.
 * [28.0] On single-player you can place more heroes by placing one in a current game then exiting when the next round appears and changing hero. Re-entering the game will allow you to place the changed hero and keep the previous one. You can do this repeatedly to have all heroes in a single level. However, XP will be split between all heroes on the map like in co-op. Patched in 28.2.

Sounds
When Lych summons:


 * [Ghostly effect]

When Lych absorbs buffs:


 * [Soul draining]

When Lych reaches its Skull Health:


 * [Strong wind followed by ghostly whispering]

When Lych is defeated:


 * [Haunted screeching and small explosion]

Quotes
"True to its name, Lych draws power from others, draining buffs from Monkey Towers and stealing any Monkey's lifeforce when sold to heal itself (avoid buff Alchemists and other familiar activated boosts!)"

- Ninja Kiwi, Version 28.0 patch notes

"When damaged to a Skull level on its health bar, the Lych is ethereally immobilized as it revives undead MOAB class Bloons, releases the stiletto-fast Lych-Soul, and steals lives as long as it remains ethereal"

- Ninja Kiwi, Version 28.0 patch notes

"Revivified MOABs and the Lych-Soul must be destroyed before Lych will return to normal state"

- Ninja Kiwi, Version 28.0 patch notes

"Due to their sheer awesomeness, Heroes are immune to the Lych's buff drain effect"

- Ninja Kiwi, Version 28.0 patch notes

"The Lych can revive all MOAB class Bloons besides BADs"

- Ninja Kiwi, Version 28.0 patch notes

Trivia

 * It was initially teased here on September 28th 2021, and was later revealed on Twitter on September 30th 2021.
 * Normal Lych has exactly 30% less health than Normal Bloonarius of the same level, and the Elite Lych has exactly 40% less health than Elite Bloonarius.
 * The resurrection of MOAB class bloons is reminiscent of the resurrection mechanic of Zombie Bloons in Bloons Adventure Time TD.
 * Lych's debut week is Week 13, which is fitting because of the perceived unlucky nature of 13. However, it did not start on a Friday, but rather a New Zealand Thursday (or Wednesday for some timezones).
 * In the real world, Lychs, often called "Lychgates" consist of a roofed porch-like structure over a gate, often built of wood. They usually consist of four or six upright wooden posts in a rectangular shape. On top of this are a number of beams to hold a pitched roof covered in thatch or wooden or clay tiles. They can have decorative carvings and in later times were erected as memorials. They sometimes have recessed seats on either side of the gate itself, for the use of pall-bearers or vigil watchers.
 * Lych name can be a pun on word Lich and Leech with former demonstrating the power of reanimating dead and latter with leeching on something.

Ninja Kiwi Blogs

 * According to the October 8th 2021 blog, Ezili likes the aesthetics of Lych.
 * According to the October 16th 2021 blog, Prince of Darkness does not like Lych being nearby the Wizard.
 * According to Ninja Kiwi's October 29th 2021 blog, Lych's backstory is considered "too spooky to share", but it is likely just Ninja Kiwi not willing to share this type of lore about Lych.