Xerneas

Attacks

Aurora Gain · 50
During your opponent's next turn, this Pokémon has no Weakness.
Light of Life · 80＋
If your opponent has Yveltal (including Yveltal-EX) in play, this attack does 40 more damage.

Legends say it can share eternal life. It slept for a thousand years in the form of a tree before its revival.