Fiendslayer Paladin

The targeting clause is doing all the load-bearing work here. A 2/2 with first strike and lifelink for is a serviceable defensive body; what reframes it is the hatch that locks out targeted black and red spells your opponents control. That clause is built as direct counterplay to the two colors that historically own the cheap, efficient kill spell: Doom Blade, Lightning Bolt, Terminate, the whole apparatus of "pay a little, point at a creature, remove it." Against those spells the Paladin simply cannot be picked as a target, so an opponent who leans on that removal is pushed toward combat, an unfavorable trade, or an answer that doesn't rely on targeting: a sweeper, a Languish, an edict effect like Diabolic Edict that makes you choose the sacrifice. First strike and lifelink are chosen to compound the immunity, letting it win fights against equal-sized attackers and pad your life while it does. The design tension lives in how narrow the protection is. It does nothing against white, blue, or green interaction, nothing against a board wipe, nothing against a black or red spell that happens not to target, and a larger blocker or a wide board still handles a 2/2 the ordinary way. This is the color-hoser instinct turned inward on the creature type: rather than making a card that punishes an opponent for playing black or red, it makes a creature that specific removal cannot see. That conditional armor, not the stat line, is the sell.