If all targets are illegal when the spell tries to resolve, the spell doesnt resolve and none of its effects happen
There are a non-trivial number of artifact creatures, but not enough good ones to justify maindecking Return to Nature
The first offers some rummaging via blood tokens (and Hazel does care about any kind of token, so these work there) and when you sacrifice those or another artifact, this gets a +1/+1 counter and you gain 1 life
You'll probably a have decent luck running this in a commander deck if you're playing 4 player style, someone's bound to have black
Feather, the Redeemed While this legendary angel can be used as a Boros commander or as a Brawl general, I mostly see this version of Feather, the Redeemed as one that will bling out Pioneer decks looking to get fresh art
Esper Terra's fourth chapter ability isn't a mana ability