Shin Megami Tensei: Digital Devil Saga

For the penultimate optional boss in the game, you'd expect Huang Long to be tough, and he doesn't disappoint.

Huang Long has several different 'modes' he goes into. The problem with this is that you have absolutely no idea what mode he's gone into until he attacks, so this battle heavily relies on guesswork. The only exceptions to this are his 'boost' mode, which he starts the battle with, and 'defence' mode, which always folllows his 'attack' mode.

His most damaging attack by far is Celestial Ray, an almighty attack that does tonnes of damage AND can cause almost any ailment to you. Think of it as a megidolaon mixed with vanity. Speaking of megidolaon, he usually likes to follow Celestia...