Bring friends, get rewardedwhile supplies last, anyway
Its also a way to discard big creatures to reanimate or instantly activate hellbent abilities
Pop a +1/+1 counter on Rikku and it's unblockable
Mana ramp cards like Rampant Growth and Knight of the White Orchid, mana rocks like Worn Powerstone and Sol Ring, tutors like Idyllic Tutor, Demonic Tutor, or Imperial Recruiter, recursion spells like Eternal Witness and Argivian Find, and card drawing/filtering spells like Rhystic Study, Dig Through Time, Wheel of Fortune, and Faithless Looting can all be cards that fit within this category
Creatures are one of the main building blocks of Magic
If you make the reanimate cost only then the total cost to reanimate and untap it will be the same as it's original mana cost, which feels flavorful to me