I would recommend you to use an aoe attacker instead of Healer cc, I feel like he's not very applicable in this situation. His range and health will really make him struggle against Le'boin and Teacher Bear. I recommend you to NOT use whale or Giraffe. Giraffe is going to be a total waste of money because crazed cat will probably 1 shot him. Whale is just gonna get massacred by Le'boin and Teacher bear, however you have Kasli and Dartanyan (2 of the best ubers in the game), remember that Kasli's kb won't work because all of the enemies are traitless. I would recommend you to use Bahamut instead of Whale and some type of debuffer/cc instead of Giraffe.
You should also level up your D'artanyan, since he will probably carry this stage on his own.
I did math, im attempting it today, D'arktanyan will deal exactly 20,493 to any traitless enemies, while on low HP he deals a massive 40,986 Damage!! Im hoping I can beat Dark Souls (Insane). Crazed Cat has 2m HP as a Enemy Unit, so it would take 50 hits to kill Crazed Cat with ONLY D'arktanyan.