Eerie Interference

A Fog that speaks white instead of green. The classic damage-prevention spell blanks a whole turn's worth of combat regardless of source; this one draws a tighter border, stopping only what creatures do, and stopping all of it. That includes noncombat creature damage too: a pinger's activated ping, a fight spell's bite, the tap-to-damage lines that live outside the combat step all bounce off it. What it leaves open is the noncreature half of the game, so a burn spell to the face, a Fireball, a planeswalker's minus, or a spell that deals damage directly still connects. That gap is the whole design, and it is also what earns the effect a home outside green, since selective, source-specific damage prevention has been white's lane since the circles of protection. The line covers both you and your creatures, so declaring blockers and flashing it in punishes an opponent who overcommits to a swing just as well as it insulates your life total against a monored clock. Held up with attackers on the board, it turns a lethal alpha strike into nothing; drawn against a deck whose reach lives in spells rather than bodies, it does the least a card can do. The deciding variable is never the size of the board but the nature of what is trying to kill you.