Murmuring Phantasm

A blank wall, and nothing else. Zero power means it never threatens to swing the corner, five toughness means almost nothing in the early game pushes through it, and Defender keeps it home where a wall belongs. This is the most austere version of a recurring blue idea: trade the entire offensive half of a creature for a body that buys turns. Decks that want to reach a late-game payoff (a mill engine, a control finish, an artifact or instant-heavy plan) need to survive the aggressive midgame without spending real cards on it, and a two-mana investment that blunts two or three attackers across a game does exactly that. The discipline in the design is the flat 0 power: a wall that could also chip in damage starts to warp toward defensive aggro, but a true 0/5 only ever does one job, which keeps it honest as a commons-tier roadblock rather than a value creature in disguise. It sits in the same lineage as Wall of Frost and the older blue defensive bodies, doing the unglamorous work of converting two mana into time.