So this came up while messing around with my reanimator EDH deck.
Say the only creature in your graveyard is {Revenant} or {Boneyard Wurn}. You have multiple effects that, at your upkeep, return target creature in your graveyard to play {Sheoldred, Whispering one}, {Reya Dawnbringer}, {Debter's Knell}. You choose all ability triggers targeting the {boneyard Wurm}. When the first trigger resolves, the Wurm has 0 toughness (0 creatures in GY) and goes to the graveyard as a result.
The other abilities, targeting boneyard Wurm, are still on the stack. Is the boneyard Wurm seen as a new entity, like how it works on the battlefield when you {cloudshift}, and the remaining triggers fizzle? Or does the graveyard function different for some reason?
Fizzle. For the exact same reason {Cloudshift} fizzles things.