Vow of Flight), which I prefer a bit more because you're "befriending" an opponent and encouraging them to deal damage on your behalf instead of mildly annoying them, but it's still cool
The trigger event doesn't have to specifically refer to legendary permanents or to artifacts, nor does it have to specifically refer to when something "leaves the battlefield." For example, an ability that triggers "whenever a creature dies" would trigger twice if a legendary creature or an artifact creature dies while Gandalf the White is on the battlefield, as would an ability that triggers "whenever a permanent is put into a graveyard from the battlefield." Look at each legendary permanent and each artifact as it exists on the battlefield, taking into account continuous effects, to determine whether any triggered abilities will trigger multiple times
Part One will discuss the actual Elves in Kaldheim and other cards that directly reference them
Even though you cant have two planeswalkers with the same name in play, you can have more than one of the same type of planeswalker in play as long as they have different names
Thats why cards that make treasure tokens are often so good, and Ognis is definitely going to make some treasure tokens