The battle will start with a 200% buffed Bore, along with some 2800% buffed peons spawning. When the base is hit, Boraphim will appear for the first time, along with Gabriels, Heavenly Hippoes, Mr. Angels, and an Angelic Sleipnir.
Once you begin, lure Bore near the base, then start spamming meatshields, Crazed Fish Cat, Island Cat, and The Flying Cat. However, don't spawn too many units, because you will need money saved up later. Once you kill Bore,spawn a few more meatshields, Crazed UFO Cats, and Flying Cats. When you hit the base, the main problem appears: Boraphim. You should have all money saved up, so spawn Ururun Cat, Holy Valkyrie Cat and Awakened Bahamut Cat. Spam meatshields, Crazed UFO Cat, Flying Cat and other units.
Angelic Sleipnir isn't much of a threat, so don't worry much about him. Just continue spamming meatshields, Crazed UFO, and Flying Cat.
If Holy Valkyrie dies, you might have a slight problem, but if Boraphim dies, congratulations! Now go and claim your victory!