Pyreswipe Hawk

Two reward structures point at the same axis here, and neither one moves without a stocked artifact toolbox behind it. The attack trigger scales its bonus off the single most expensive artifact you control, so the payoff climbs with the ceiling of your artifact suite rather than its width: one bomb-sized rock or Voltron piece does more for it than a pile of cheap trinkets. The expend clause runs on a separate meter entirely, keying off the sixth total mana you spend on spells in a turn to steal an artifact for as long as this bird stays on the battlefield. That conditional tether is the discipline paying for a repeatable theft effect: lose the flier and the borrowed artifact snaps home, which frames the whole design around protecting the body rather than casting it and forgetting it. What ties the two abilities together is that both want the same thing you already want in an artifact-heavy deck: the attack rider makes your expensive artifacts double as a pump spell, and the expend theft can rip the biggest artifact off an opponent's side, which then feeds the attack rider on the following swing. It is a top-end aggressive threat built for a deck that treats artifacts as its resource base, asking you to spend past six mana most turns and to keep the evasive body alive long enough for the borrowed goods to matter.