A few Owlbrow will spawn at the start. After the base is damaged, Director Kurosawah (Black) will spawn with more Gabriel and Doge Dark, along with Boraphim (Angel). Doge Dark and Gabriel will spawn at a moderate rate throughout the rest of the battle, and another Boraphim will eventually come.
Make sure you have 4 meatshields. Bring both types of flying cats. If you have Jizo or Momotaro, use them in their unevolved forms. Use Babel if you have him (which you won't.) Also bring Jamiera to take down Kurosawah.
Bring a Cat CPU to help with meatshielding. Start by gathering money and using Erasers to defend against the Owlbrow. Once you have enough money, start spawning a few Flying Cats (Both types) until the Owlbrow is defeated.
Once Kurosawah and Boraphim spawn, let Boraphim get close to your base.
Turn on the Cat CPU when he gets about halfway. Then let your Flying Cat stack build up and destroy him.
After the first Boraphim dies, turn off the Cat CPU. Turn it back on when the second Boraphim comes.
Once the second Boraphim dies, you've basically won.