Edison Format · March 2010
Destroying all other monsters during the End Phase is a Trigger Effect.
When a face-up "Yubel – Terror Incarnate" is sent to GY, removed from play, or returned to its owner's hand, its effect to Special Summon "Yubel – The Ultimate Nightmare" activates. This effect cannot be activated when it is returned to its owner's Deck.
When "Yubel – Terror Incarnate" is removed from the field, its owner activates its effect. (If your opponent controls your "Yubel – Terror Incarnate" when it is removed from the field, you get the effect, not your opponent.)