Vortex: Deadly Master of Air/BMC

Vortex: Deadly Master of Air is a MOAB-Class Bloon found in the Vortex event in Bloons Monkey City. It has a boss health bar which increases every time it levels up after you complete a level of the event. Upon popping Vortex, you will see Vortex saying "You win... this time!" and receive the relative tier of CT Milestone worth in rewards. If you fail to pop Vortex, you will receive a message with the normal "DEFEAT!" showing, and text that says: "...But the Boss is damaged. Chase it down and try again!" Like Bloonarius, the Bloon Beacon is needed to summon the boss out of hiding.

It also appears in BTD5 Mobile during the Boss Event on Skull Peak.

Health
Health + RBE table below for the first 25 levels.

Vortex's health for any level past level 19 can be determined using the equation below, where "x" is the level to be accounted for:

1800² - 44100x + 326700, x ≥ 20 or 900(2x² - 49x + 363)

Speed
It moves at a relative speed of 0.2 of the speed of a Red Bloon.

Pulse/Shockwave
Every 7 sec, the Vortex starts a pulse in 100 px range, which stuns (depending on stun level) and slows towers in range for 6 sec.

The stun time is based depending on level and Vortex health.

The stun level is calculated like this: stunLevel = 0.2 + (0.1 * skulls destroyed) + Level * 0.02. 1 Is max and probably means that hit towers are turned down fully 6 sec and are only 1/7 as effective as if it would be not stunned.

Properties and Immunities

 * Vortex doesn't have any special physical properties except of being a MOAB-Class Bloon, so it can be hit by any tower (except ice and glue)
 * MOAB Assassins damage is reduced from 750 to 375.
 * It can be affected by the Boss Blast and Boss Chill, which cost Bloonstones. Absolute Zero and Pop and Awe also work, but only on the Mobile version.
 * You get 1.5 cash per damage on Vortex.
 * Moab Mauler does 10 bonus damage, but SHREDR Spikes does 2 instead of 4 damage.
 * Vortex cannot be sucked up or damaged by a 4/x Bloonchipper in BMCM

Strategies

 * See also: Boss Bloon/Strategies
 * A single Super Monkey, placed near the center of the track should be able to defeat Vortex on low levels. Additional towers would be needed to avoid loss of life to any minor bloons that leak through.
 * The battle does seem to consist of multiple continuous rounds, particular as evidenced by production from Banana Farms, as well as deployment of crates.
 * Spamming and selling MOAB Assassins could be used. It becomes effective at the end to do some damage against it. With Monkey Tycoon level 13, you can spam them without a loss in money (Activating the ability would do damage to Vortex, therefore giving you cash to re-buy the ability) and your damage is only depending on your speed. It is possible although very challenging to kill the level 20 boss in four tries and no "consumable items" with MOAB Assassins as the main damage.
 * Vortex is immune to slowing and stunning, so Sabotage Supply Lines, Cripple MOAB and Pop and Awe will not work against the blimp.
 * However on mobile, Absolute Zero can slow down Vortex.
 * MOAB Maulers do deal more damage to it than Missile Launchers, as Vortex is considered a MOAB Class Blimp.
 * Many 0-0 Dartling Guns, with some lead popping power, could be a viable option, considering their quick fire rate and the ability to aim at Vortex or a large rush of bloons. Vortex's large size makes it easy to hit, even with the spread.
 * 1/3 Spike Factories are very effective, and are a good supplement towards 3/0 tacks or 2/3 bombs (or sniper or dartlings).
 * Spamming Tack Sprayers around the curving track can easily destroy Vortex at lower levels and a efficient strategy up to stage 10.
 * Boss Bane will instantly defeat Vortex level 1.
 * Heli Pilots with 3/x are also very effective add a additional 2/x Heli Pilot to reduce damage and increase efficiency.

Trivia

 * Vortex is, after the BFB, the ZOMG and the Bloonarius the Inflator, the fourth MOAB-Class Bloon to have eye symbols.
 * It is also the only one besides the Elite form of Lych to have more than two eye symbols.
 * Vortex is, after Bloonarius the Inflator, the second boss Bloon in BMC.
 * Vortex resembles a blue DDT or a recolored ZOMG bloon with black shark fins.
 * Vortex has a propeller in the front on its icon, but in-game, it does not have one. However, this is not the case in the mobile version. Its icon also shows it tip is wide, similar to Bloonarius however in-game it is streamlined and has a tip.
 * Vortex seems to be the air-based counterpart of Blastopopoulos: Demon of the Core, since they stun Towers and share a similar structure. However, Vortex uses a pulse instead of a fireball.
 * In the Mobile version, Absolute Zero can slow Vortex when on the track, allowing towers more time to attack it.
 * Vortex is slightly larger in BMC Mobile than its flash counterpart, along with slight changes in style.
 * In BMCM, Vortex's hitbox is a circle, and can be damaged from road spikes even if it is not touching them completely.
 * Vortex's ability to stun towers is useless against Monkey Aces. The tower's runway will have the stunned animation, but the plane itself will continue to attack as normal.
 * Vortex is the only boss bloon that doesn't appear in Bloons Super Monkey 2
 * As seen on the in-game banner for the Bloonarius event, Vortex is Bloonarius's little brother.