No problem, we have tons of ways to get them back
Due to things like Sorin, Grim Nemesis functioning as Corrupt in addition to a more-than-fine win condition, and Dark Petition finding Virulent Plague to shut down tokens and some planeswalkers, everything seems to be in place for (almost) Mono-Black Control to exist
With trample, Kami of Transience can push heavy amounts of damage and even if your opponents can answer it with a removal spell, it returns to your hand whenever an enchantment enters your graveyard
Always ensure that the type of postage is adequate, if you are sending 0-20$ worth of cards, use postage that covers that amount, you may risk without it as the risk-benefit (cheaper price) might be worth it for you
Unlike some other Universes Beyond sets of MTGs past, Final Fantasy will indeed be Standard legal
Meanwhile the Provisioner is going to be making Treasure tokens most of the time like a Lotus Cobra that can pool Treasures for big explosive turns