Sustaining Spirit

A static prison wall, written as a creature you have to keep feeding. The damage-prevention clause is the kind of effect that usually arrives as an enchantment or a one-shot fog (preventing combat and burn from dropping you below 1 life), so stapling it to a 0/3 body invites all the wrong instincts: chump it, race it, ignore it. Note the scope: this stops only damage, not direct life loss, so an opponent draining or sacrificing your life total walks right past it. Cumulative upkeep is the leash that makes the floor temporary. Each turn it survives, the age counter tax climbs, so the protection is real but rented; you are buying turns, not buying out the game, and eventually the upkeep cost outruns whatever you can pay. Everything strategically interesting here lives in that escalation. A permanent that can never let you die to damage is a degenerate object in the abstract, so Alliances priced the safety in a currency that compounds: the longer you want to live at 1, the more mana you bleed to stay there, until the engine you built around the effect starves the effect itself. It reads as a defensive wall, but the axis that matters is the countdown. You are not asking how long the Angel can block; you are asking how many upkeeps you can afford before the spirit you are leaning on sacrifices itself and hands your life total back to the opponent.