Thunderblight Ganon

Thunderblight Ganon is a boss in The Legend of Zelda: Breath of the Wild. It is a giant monster sent by Ganon to guard a Divine Beast serving as a dungeon.

Hyrule Castle
If the player rushes off to Hyrule Castle before freeing the Divine Beasts, Thunderblight Ganon along with the other three Scourges of the Divine Beasts will appear to fight Link back to back in a boss battle.