Fangren Marauder

A 5/5 for six is under rate, and the gap is deliberate: the body is priced down because the lifegain rider is meant to carry the slot. The trigger pays a flat five every time an artifact goes from the battlefield to a graveyard, and the load-bearing word is "an," not "your." It does not care whose artifact dies, so an opponent cracking their own mana rocks, a board sweep collapsing both sides, sacrifice fodder fed to an outlet, all of it feeds the same five-point gain with no cap and no targeting clause. That is what defines the card's strategic axis: it wants a board state where artifacts are constantly trading and dying rather than sitting still. In a deck built around artifact attrition, each of those small losses becomes a swing, and a single combat-and-sacrifice exchange can erase an aggressive curve's worth of damage in one turn. It is an engine piece for grindy artifact decks rather than a creature you cast for its stats; the more permanents are churning through graveyards, the more the rider justifies the six mana. Strip the artifact churn away and the trigger simply never fires, leaving you with a 5/5 body and a dead ability, which is precisely why the lifegain is written to key off the whole board rather than just your half of it.