How do you beat the final boss in dragon quest heroes

Keep firing ammo. When he gets after your engine, just kill him over and over while Slival keeps throwing ammo. You can get in his tank while he's ressuectiong and start towards the engine room even if it's locked. There are obstacles on the way there. When he ressurects, he will be distracted with you. You also have less work to do when there engnine does die. If he shoots fire around him, jump at the right time and then kill him. Same if he shoots it directly at you. You can elasto blast him while he's in the process of making fire. If he is shooting it directly, you can also move to the side. <3 Good luck, Hooly is harder to defeat.