Halvar, God of Battle assists in cheating around equip costs, which can put a powerful Equipment onto a creature for free that would otherwise cost a hefty amount of mana to do so
So if paper rarities do count, I'd like to start playing with Hymn to Tourach and High Tide and Blue Elemental Blast, please
And bouncing has a lot of flexibility as a way to survive removal or blocks, adding a useful tempo element, reloading a creature with a powerful enters-the-battlefield trigger, dealing with auras and so much more
Creature - Cleric Spirit Color tag templates(None) Solemn Simulacrum When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle
Some cards have been printed in multiple sets, and older sets are generally worth more than newer printings
It once dominated multiplayer tables so much that False Cure became almost a requirement