It must be mohawk
I'd spam rock and doron. Your btrain isn't strong enough to kill a doge dark, so send a can can with double money and a fast meatshield to gain money. Use a rich cat too with an ITEM sniper. A Doron, Rock, Octo, Can Can, a fast meatshield (Manic Mohawk or Eraser)
And whatever you want you think would help
(Bad Guys) Fast meatshield, Rock
Can Can, Octo, Doron, |Whatever you want|
If you use Shitakiri Sparrow/Grand Chun Chun Hunters, use him. Chun Chun not only is a combo slave but he does okeyish damage with Surge Immune. Chun Chun can out-range Kappy Jr. with a little chip of miniwave damage to others. He's pretty good for this stage but I think people will just use the combo.
Aer. Aer has always been an outlier in the Elemental Pixies him not having an effect against an alien and being treated as a sniper. With his ultra form finally gives him an effect against aliens that is Knockback. It is not worth getting to level 60 even though it has good range. (15 dark catseyes ain't worth it)