Center Soul
Protection is the deepest defensive keyword white owns: against the chosen color it prevents damage, blocks targeting, stops enchanting and equipping, and keeps the creature from being blocked by anything of that color. The wrinkle here is rebound, which turns a one-shot trick into a two-turn commitment. You cast it now and get one free recast on your next upkeep, naming a color again the second time. That second casting is the constraint that pays for the flexibility: you do not get to bank the spell and fire it on demand. The free recast lands at the start of your turn, before combat and before you have read your opponent's hand, so the protection it grants is committed early rather than held as instant-speed insurance. The first casting still does the reactive work a combat trick asks of it (fizzle a targeted removal spell, slip a creature past a blocker, push damage through), and the second is a guaranteed follow-up an opponent has to respect without being able to bait it out. It rewards a board built around a single threat worth protecting twice rather than a wide one where one creature's survival barely registers, which is the quiet way rebound shapes the kind of deck it belongs in: less an answer you hold up than a tempo plan you start and finish over two turns.
