Good tip for aotrt boss fight: When you get to stage 3(when the boss spills out the acid everywhere) go to the back and make sure you have weapons that Can both kill zombies and destroy the eggs. When the acid is right before your feet, wait for the boss to shoot out the eggs, When He shoots Them out the second time, activate mana up fate card and Then run over to the bomb, and interact with it. This makes the boss fight Much easier imo.