Waterblight Ganon Boss Fight
This unholy abomination can be taken down if you follow this strategy. Dodge his spear at the right time to slow the action down. That's your chance to let him have it. when he's stunned, let him have it some more until he recovers. Rinse and repeat until his life bar is half empty. Watch out for his spear. It hurts a lot. Also, a Guardian weapons may make quick work of the first phase.
He'll flood the arena and make 4 platforms appear. Get on one and try to shoot his eye to stun him. He'll conjure up some ice blocks and throw them at you. Like before, shoot the ice blocks to break them. When he's stunned, let him have it. When his life bar is almost down to zero, he'll use his laser pointer to aim for you. Try to deflect the laser back at him. Alternatively, you can just keep shooting his eye until he dies. After he's dead, you'll be given a Heart Container. Now, go activate the main control panel. Once you do however, you will never be able to return to the dungeon. So make sure you opened all the chests.