Strategy 1 (Overkill)
Spam front row and drop a ring girl cat to halt and deal with initial wave of peons, all the while build up the worker cat level. When under control let your pack get to the base and die, save money.
Then bring in Shingen and start meat shield spamming, drop Mekako and bring in the other 2nd row cats, better to save Bahamut for a clear shot at the boss but not critical.
I'm quite new to the game and this was my first shot at this stage, I realise this strategy is very dependent on specific cats but most are, adaptation is always possible. Good Luck!
Strategy 2 (Ft. Oda)
Oda outranges Dark Lazer and permafreezes it without any ITF treasures. Bring something to counter the Dobers and it's an easy true form.
Strategy 3 (Prof. Cat Jobs and Bombercat)
Lineup: meatshields (preferably crazed cat, crazed tank and eraser), cheap and spammable area attacker (e.g. Paris), Crazed Sexy Legs (not sure if this is necessary), high damaging area attacker (e.g. Bahamut), Prof. Cat Jobs, Bombercat, a cat that will help against the Dobers (e.g. Octopus), decent ranged attacker
Note: this will only work with anti-black treasures from Into The Future
The key to this is good timing. Prof. Cat Jobs needs to weaken Dark Lazer, then Bombercat will freeze it, and then Prof. Cat Jobs weakens it again, then Bombercat freezes it again. This will continue until there are enough Bombercats to permafreeze the Dark Lazer until it is knocked back.
At the start, stall the Doge Darks with your meatshields and save up for your high damage area attacker to take out the enemies. Also spam bombercat to assist with taking them out, and spawn in Prof. Cat Jobs.
After the base is hit, Prof. Cat Jobs should be knocked behind the base. This gives it more survivability against the Dobers, whose shockwaves will one shot it. By the time that it reaches Dark Lazer, the Dobers should be dead.
Prof. Cat Jobs will attack Dark Lazer occasionally, lowering its attack to 1%, meaning that Bombercat will not be one-shotted by the boss. If the timing is correct, the boss will either be weakened, frozen or both at every single frame. With a stack of bombercats, the boss will be permafrozen until knocked back. If it is knocked back and hasn't already been so, your entire stack of Bombercats will likely die, but you can get a new stack easily. The boss only has 2 knockbacks.