Blade Maelstrom Ability: Covers the area in an unstoppable storm of blades.
~ Bloons TD 5 Description
Blade Maelstrom is the final upgrade on the second path of the Tack Shooter in BTD5. It is unlocked upon reaching Rank 20. It is the special ability for the Tack Shooter in BTD5, BTD Battles and BMC. When activated, the Blade Maelstrom rapidly shoots two streams of blades, which spiral outwards. It costs $2295 on Easy, $2700 on Medium and $2915, Hard and $3240 on Impoppable. Its ability cooldown only lasts for 20 seconds.
Each of the blades have unlimited pierce, making it good for thick groups of bloons (Helpful if Regen Farming gets out of control and it's cheaper than Ground Zero). However, you may need 2 or 3 to destroy all Regenerating Bloons. Several of them can destroy a whole map of regenerating Ceramic Bloons.
Going against the direction of the track, sometimes known as going against the grain, does more damage to to bloons, so positioning the Blade Maelstrom is important.
Blade Maelstrom will deal more damage to bloons closer to its proximity, due to the higher density of blades.
Blade Maelstrom is one of the more cheaper ways to pop the Ceramic Bloons on rounds 63, 76, and 78, although you would need to give Camo detection on the Blade Maelstrom to pop the camo rush on round 78.
Despite the description stating it is "unstoppable," Blade Maelstrom will be stopped by Lead Bloons. This can be prevented by a Monkey Intelligence Bureau, however, unless your strategy is highly reliant on MIB it is generally not worth it.
It is possible to take down the outer layer of a MOAB with this ability if players time it correctly.
There is a bug where the ability will never hit Camo Bloons, even if the tower is next to a tower permitting Camo detection. This doesn't happen in BTD5 Mobile/Steam or BTD6.
The Blade Maelstrom has the fastest cooldown in BTD5, taking only 8 seconds to recharge in fast forward mode.
Blade Maelstrom is the cheapest Activated Ability in BTD5, costing $4140 (in total as a 0/4) in Medium. The second cheapest is the Absolute Zero from the Ice Tower, costing $4800 (in total also as a 0/4).