Floor 21 is the twenty-first level in Heavenly Tower.
- Those Guys is spawned infinitely, stack every 2~6 seconds.
- Up to 10 B.B.Bunny can be seen before boss fight, stack every 1.3~3.3 seconds40~100f.
- After 10 seconds, 1 St. Pigge the 2nd appears.
- After 13.3 seconds400f, 2 Shy Boy appear, delay between them is 3.3~6.7 seconds100~200f.
- When Base HP is 99%, Red Cyclone appears with:
- 4 Capy, delay 1.7 seconds50f;
- Group of 2 Blitzen, respawn twice, delay 93.3~94 seconds2800~2820f, a total of 6 of them can be seen.
- 6 B.B.Bunny, delay 1.3~2 seconds40~60f. One B.B.Bunny will be spawned every 66.7~67.3 seconds2000~2020f.
Heavy hitting or anti-Red Area attackers are almost required. The Capys guard the Cyclone, while both will shred through any defense you have. Thundia can be a good choice, for her power and triple damage against Reds. Once the Capys are gone, then the Red Cyclone is left defenseless against knockbacks, freezes, etc.
Money is not too much of a problem, as the B.B.Bunnys at the start produce a good amount of cash, but maintaining it can be a problem.
Strategy 1 (Uber-less Line Up):
- Mohawk (20+60), Manic Mohawk (40), Eraser (20+60), Manic Eraser (40), Sanzo (30+18), Macho Legs (20+60), Manic Macho Legs (40), Manic King Dragon (40), Crazed Bahamut (30) annd Ururun (30).
- Demonstrated video: 
- Mohawk (20+60), Manic Mohawk (40), Eraser (20+60), Manic Eraser (40), Drone (40), Manic Island (40), Dragon (20+60), Holy Valkyrie (30), Awakened Bahamut (30) and Titi CatCCMerc Storia (any level)
- Demonstrated video: 
- Four Meatshields (Crazed Wall, Eraser, Manic Mohawk and any extra), Manic Macho Legs Cat, Sanzo Cat, Can Can Cat, Luxury Bath Cat, Ururun Cat and Miraculous Mobius.
An actual spam to win. Just get Mobius and Ururun into the fight ASAP against the starting Shy Boy, then the big wave of Capies, Blitzen and Red Cyclone. Can likely replace Mobius with Raiden or Kamukura.
Strategy 3 (Uberless):
- Units: 3 75$ meatshields (I used Manic Mohawk lvl 20, Mohawk lvl 20 and Gold Cat lvl 30), Jiangshi, Sanzo, iCat or anything that freezes red (I used Gentlemen Bros), Manic Macho Legs lvl 20 (Crazed can be used but Manic Macho Legs recommended), Crazed Dragon lvl 20 (if manic the better), Awakened Bahamut (can be crazed if you prefer a stable, more long battle) and any other area attack unit that outranges Capy Pole Vaulter
- Powerups used: None, but bringing a CPU and Rich cat will speed up the process.
Start the battle by spawning one Manic Macho Legs, some meatshields and your proccers (Sanzo & a "Freeze red" unit). Once the Bunny's are dead you should have enough money to stall the 2 buffed Red Faces. After they are slowed down by Sanzo deploy your Awakened / Crazed Bahamut (before killing the faces make sure your wallet is around 4-5). After they are dead max your wallet and dont spawn any more units (if you used Crazed use Cat cannon to clear out the peons then your ms should rush the base instead)
Once the boss wave triggers let them kill your units, wait till some support units reach the base (or near your Crazed Bahamut(if you used it)) turn on Cat CPU and watch the beautiful scenery. Sanzo and your "Freeze Red" unit should be able to stall the Cyclone while your damage dealers will take care of the Capy's. Once the Capy's are dead, turn off CPU and just spam MS, MML and Crazed Dragons (you can leave it on if more Blitzen's spawn)
Additional note: Maxed ITF treasures recommended