I wish the DRK invul wasnt so bad, like really even after they changed it, its still trash.

Things that can happen:
#You fall down to 1 HP, you immediately use an attack > it doesn't register that you already have the buff because of server ticks > you get no healing from the first attack> you die because you cant fullheal yourself in time
#You Fall down to 1 HP > there is no enemy to attack or you get stunned > it runs out and you die
#You use it in a dungeon but the healer keeps you barely alive and it doesnt trigger > it runs out > you die because the healer fails to heal you and you never got the self heal effect