Warrior Angel

A six-mana 3/4 flier was already an awkward rate in 1998, and the lifegain clause was the apology pinned to it: every point of damage the angel deals refunds itself as life, so the body that trades poorly on the board buys you time on the clock instead. The mechanic predates the lifelink keyword by years, which is why the effect is written out longhand, and the difference from modern lifelink is not its scope (lifelink also pays on any damage, not just combat) but its shape: this is a triggered ability that goes on the stack rather than a static replacement, so the life arrives after the damage resolves and can be responded to. In practice the job is to swing, eat a chunk of an attacker, and pay back the difference between a race you were losing and one you can survive. This is white's recurring answer to aggression cast as a creature: not a wall, not a removal spell, but a flier that defends the air and stabilizes a life total in the same attack step. As a piece of white's lineage it sits early in a long line of midrange angels meant to flip a damage race, the structural ancestor of the cleaner, cheaper lifegain fliers that came later and made this one's rate look its age.