When this creature enters, if you control another Elf, create a 1/1 green Elf Warrior creature token.
Dwynen's Elite's ability checks at the moment it would trigger to see if you control another Elf. If you don't, the ability won't trigger at all. If it does trigger, the ability will check again as it tries to resolve. If you don't control another Elf at that time, the ability won't resolve and none of its effects will happen.
