The Walls of Ba Sing Se

A 0/30 body that never attacks is not the point; the second line is. Blanket indestructibility for every other permanent you control (not just creatures) rewrites how removal works against you. Board wipes that destroy stop mattering. Combat that would trade dies to friction. Your lands, artifacts, and planeswalkers all shrug off destruction as long as this stays on the table. The design tension is deliberately obvious: at eight mana with defender, it does nothing to close a game, and it leaves a glaring seam. Indestructible answers nothing to sacrifice, exile, bounce, counters, or effects that reduce toughness to zero or move a permanent to the graveyard without destroying it, so the wall invites exactly the removal that ignores it. And because the grant reads "other permanents," the wall itself stays destructible, which makes it the natural target: kill the 0/30 by any means and the fortress it was projecting collapses in the same instant. That is the whole strategic axis. It is a lynchpin that protects everything except itself, a defensive anchor priced high enough that a deck built around it spends the early turns surviving to deploy it, then spends the turns after surviving the moment someone finds the answer to it.