Samite Ministration

Damage prevention with a built-in color hate clause: protect yourself from any one source, and if that source happens to be black or red, the prevented damage flips into life gain. That second sentence is the design idea, and it dates the card to an era when Invasion's gold-flavored block was explicitly building white as the enemy of black and red aggression. Most prevention spells of the period (Healing Salve, the older Samite Healer effects) were colorblind: they stopped damage without caring where it came from. This one rewards a metagame read. Against a creatureless mono-red burn turn or a black-source haymaker, it does double duty, blanking the damage and recovering the life total in one go; against blue, green, or white, it is plain prevention with an upside you never collect. The "source of your choice" wording also matters: you name the source when the spell resolves, so a single big attacker, a Ball Lightning, or a one-shot burn spell can be neutralized outright, but a swarm of small attackers slips past because prevention attaches to one source, not all of them. It is a sideboard answer in spell form, narrow by construction and pointed at exactly the two colors the block cast as white's natural enemies.