Round 4 is the 4th stage of Colosseum: Half-Off Plus. Previous stage: Round 3. Next stage: Round 5.
Half-Off+: Special超半額セット EX
Special Unit deploy costs are halved, with deploy cooldowns shortened by 30%! Plus, two units will be deployed at once!
Special cats have cooldown shortened by 30% and spawning one will spawn another instantly.
One rule applies to the whole run; the icon at the bottom-left of the stage select confirms which one is in effect. Some Cat Combos may not activate under it.
Znache, Zuche, Zigge and Zang Roo revive after dying — without a Zombie Killer they keep coming back. Bring one to end the loop.
ZOMBIE CAT B Zombie Killer — stops the revive so it stays dead. Also fits “Clear the crowd.” 
BAKERY CAT A Zombie Killer — stops the revive so it stays dead. Also fits “Out-range Relic Bun-Bun.” 
CHEERLEADER CAT A Zombie Killer — stops the revive so it stays dead. Also fits “Out-range Relic Bun-Bun.” 
MIGHTY REKON KORPS S Zombie Killer — stops the revive so it stays dead. Also fits “Out-range Relic Bun-Bun.” 
MR. B Zombie Killer — stops the revive so it stays dead. 
ONMYOJI CAT A Zombie Killer — stops the revive so it stays dead. Also fits “Out-range Relic Bun-Bun.” Relic Bun-Bun is Relic. Anti-Relic units take less damage and deal more.
MASTER URIL A Esoteric Uril: Strong against Relic, Aku (Deals 1.5x damage, only takes 1/2 damage) Also fits “Out-range Relic Bun-Bun.” 
CALLIGRAPHY CAT A Strong against Relic from long range, Curse-immune. Also fits “Out-range Relic Bun-Bun.” 
DELINQUENT CAT A True Form also targets and freezes Relic. Also fits “Clear the crowd.” 
CATMAN S Massive Damage vs Relic (True). Also fits “Out-range Relic Bun-Bun.” 
RED RIDING MINA A 50% Weaken vs Relic softens Relic enemies for the rest of your team. Also fits “Out-range Relic Bun-Bun.” Relic Bun-Bun reaches 200 range. Units that out-range it can chip safely without taking hits.
GROSS CAT A Range 350 — fires from beyond its 200. MASTER URIL A Range 405 — fires from beyond its 200. Also fits “Counter Relic.” 
SALON CAT S Range 350 — fires from beyond its 200. Also fits “Clear the crowd.” 
FIGURE SKATING CATS A Range 355 — fires from beyond its 200. Also fits “Counter Relic.” MIGHTY REKON KORPS S Range 470 — fires from beyond its 200. Also fits “Stop the revives.” Relic Bun-Bun has a deep HP pool (3,000,000+ even before stage magnification). Heavy single-target burst shortens the fight.
BAHAMUT CAT S Huge multi-hit burst — a story-unlock powerhouse that deletes tanky enemies. MIGHTY REKON KORPS S Among the highest single-hit Area damage available. Also fits “Stop the revives.” 
GAIA THE CREATOR S Long-Distance multi-hit with Insane Damage — a generalist wall-cracker. Also fits “Out-range Relic Bun-Bun.” 
CRAZED MONEKO A Big crit burst against tanky/Metal targets. 
CHILD OF DESTINY PHONO S Big Multi-Hit Massive-Damage bursts from safety. Also fits “Out-range Relic Bun-Bun.” 8 enemy types stack up here. Area attackers hit the whole push at once instead of one unit at a time.
MASTER URIL A Area attacks hit everything in range. Also fits “Counter Relic.” 
VENGEFUL CAT D Area attacks hit everything in range. Also fits “Stop the revives.” 
NERD CAT A Evolved/True hit groups over a Long Distance band. Also fits “Out-range Relic Bun-Bun.” MIGHTY REKON KORPS S Long-range (Omni Strike in True) Area clears groups front and back. Also fits “Stop the revives.” 
URURUN WOLF A Area attacks hit everything in range. Also fits “Out-range Relic Bun-Bun.” 
The castle you destroy to clear the stage.