Blade Maelstrom is the final upgrade on the second path of the Tack Shooter. 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.