Archmages Charm is extremely pushed, a solid permission spell, a good way to build card advantage for hitting land drops, and a fantastic tool against Deaths Shadow, Wild Nacatl, Goblin Guide, Pyxis of Pandemonium, Champion of the Parish, Aether Vial, Delver of Secrets, Hardened Scales, Amulet of Vigor, Benthic Biomancer, Glistener Elf, Noble Hierarch, Viscera Seer, and sometimes even Hexdrinker (just to mention a few)
and Sven, the lovable reindeer
Cards like Gunner Conscript , Moira Brown , and Mister Gutsy all love to play with auras and equipment, going from relatively minor threats to game-ending monstrosities once fully kitted out
Some spells from the time of Saviors of Kamigawa can splice onto arcane spells, or cared about the spell type
And, oh yes, the creature gains indestructible, making it really hard to kill again