He also tends to avoid death due to his cunning and intelligence, and use of alternate forms and his creations, the Terrible-Monsters, to avoid detection. He has been defeated many times but proves to be immortal because of his eternal resentment for Ultras while he can be felled in battle, it is impossible to truly kill him, as eventually his unceasing grudge will cause him to be revived. Yapool (ヤプール, Yapūru) is an evil entity and the main antagonist from Ultraman Ace.