The Ex Appears is the first stage in Forbidden Bride Pt II.
All enemies are alien, so an anti-Alien set up works great.
The main boss is Gorilliam, to defeat him easily use an Alien freezer such as Surfer Cat. Wheel Cat can be used to clear the peons, but do not even think about using him against the boss, as he will be out-ranged.
This stage is really easy if the player has decent level cats (lvl. 25 Surfer Cat is enough to one-shot the Shibaliens), because it takes some time before the boss starts to kill your meatshields (and this time can get longer due to his warp ability).
Warp Blockers are not necessary unless you don't have any anti-Alien Treasure, you have really low-level cats or if you don't have strong attackers against aliens. Also, the boss doesn't have 100% warp chance, so he can't break through your meatshields easily.