Personal Sanctuary

The asymmetry here is the whole design: protection that only covers you, and only while the clock is yours. The blunt reading misses the point. Because opponents attack and burn you on their own turns, when this enchantment is dormant, it does almost nothing to slow a race or an aggressive opponent. What it actually does is break the symmetry on damage you inflict on yourself. The classic partners are the symmetric burn enchantments and sweepers: cast Earthquake for a big number and your own life total stays untouched while every other player and their board pays full freight; run Manabarbs and let the table take the ping each time they tap for mana while you spend yours for free. It turns a Pyrohemia or a Sulfuric Vortex from a shared liability into a one-sided clock. The limits are precise and they keep the effect honest. It prevents damage dealt to you, the player; it does nothing for your creatures, gives no hexproof or indestructible, and offers no shelter against removal or any noncombat effect that is not damage. And the window closes the instant you pass the turn, so an opponent's combat step and instant-speed burn land normally. This is a sustained, no-upkeep prevention shield built for one narrow but powerful job: making your own scorched-earth plan hurt everyone except the person who cast it.