Enraged Giant
The printed cost reads six, but improvise means only the red pip is genuinely load-bearing. Tapped artifacts cover the generic while never touching the colored requirement, so a board littered with Servos, Thopters, and other cheap trinkets drags the real cost of this 4/4 down toward a single red. Haste and trample are the reward for cheating it out early: a body that swings the turn it lands and refuses to be chump-blocked into nothing is exactly the closer a go-wide artifact shell wants to slam ahead of curve. The bargain is the usual one for cost-reducers, though. Cast honestly off six lands, it is a 4/4 with two keywords, a rate no one has willingly paid in years. The floor is that ugly six-mana beater; the ceiling is a tempo swing that lands turns earlier than its printed value suggests. Which one you get depends on how many artifacts you can tap on the turn you play it, and that number only climbs high enough when the metal is already flooding the board. Surround it with disposable artifacts and this is a discount finisher; run it as a standalone Giant and you have overpaid for haste.

