Blunt the Assault

A Fog that does double duty, with a lifegain rider that prices the spell differently from a pure prevention effect. A plain combat-damage prevention spell buys a turn and nothing else; this one scales its payoff to the size of the board, counting every creature on both sides, so the wider the swing it blunts, the more life it banks. That coupling is the whole design tension: the spells that most want to be stopped (a fully committed alpha strike, a token army crashing in) are exactly the boards where the lifegain reads largest, and your opponent's creatures count just as much as yours. The prevention half guarantees the floor (you survive the swing); the gain half turns survival into a cushion that can swing a race outright. It asks more of its mana than a one-mana prevention spell, but it pays the difference in a number that grows with the threat it answers, which is a cleaner way to price the effect than simply making the Fog cost less. A Fog that rewards letting the board get crowded before you cast it, then converts that crowd into life rather than just denying damage.