An attorney died in 2020 and is being reincarnated in the world of Fairy Tail. Forgot about his identity in his previous life, he mastered "Water" magic.
Water is made from hydrogen and oxygen.
Dragon Slayer Magic, Lost Magic, Demon, etc; let's just bomb them with hydrogen bomb.
Mushroom-shaped smoke appears and that explosion destroys everything.
Slow pace, so be patient....