In Phantasm, in addition to being an attacker on par with Raviel, he can also be active in aspects other than effects, such as protecting Raviel's cost and generated tokens from battle, aiming for Armitile materials and additional effects of awakening
Because the one-shot effect that returns the card isn't an ability that goes on the stack, it won't cease to exist along with the leaving player's spells and abilities on the stack
However, for all that detailed complaining about the difficulty of pulling the fancy cards, I do need to stress what a difference the Ancient and Future cards have made to the set
Fastbond often catapults its controller ahead by producing huge amounts of mana and landfall triggers
It's because it's part of the MTG Power 9, a set of the nine most powerful MTG cards ever printed, all of which are on the MTG Reserved List, never to be printed again.