This stage begins with 3 Doge Darks and a Sir Seal being spawned, with these two groups reappearing constantly until the base is hit. When the base does get hit, Professor A., 3 Brollows, and a massive horde of Gory Blacks, Dagshunds, and Angelic Gories all spawn at once. From then on, Angelic Gories and Gory Blacks will be spawned in waves.
Powerups Required: Rich Cat (necessary), Cat CPU (helpful)
At the beginning, stall using your Eraser Cats, and slowly kill the Sir Seals with a big stack of Paris Cats. Don't send your big attackers just yet; the Brollows will kill them off. Once your stack hits the base, immediately start spamming 3/4 meatshields. Spawn Ururun Wolf and Holy Valkyrie after the meatshields, and Catdam and Bahamut when (yes, when, not if) they get close. Turn on Cat CPU (if you have it) when a few Gories die.
What makes this strategy work is that the enemy base will eventually run out of Gory variants and Dagshunds to send your way. Awakened Bahamut serves here as a crutch to give you enough time to build up a sizeable stack of Paris Cats/Crazed Sexy Legs. From there, the CPU and attackers should be able to output enough DPS to kill all the Gories and Dagshunds. Once that happens, the level is almost over; Professor A. has low health, mediocre attack power, and shorter range than Catdam.