Arbalest Engineers

The three-mode enters trigger is doing something quietly unusual for a body this small: it lets one creature answer three different board states without asking you to commit at deckbuilding time. The Tim-style ping picks off a mana dork or an X/1 blocker; the counter-plus-trample-and-haste line turns the Engineers into a combat enabler that pushes damage through the turn it lands; the Powerstone builds toward whatever artifact plan the deck is running. What ties it together is that the mode is chosen when the creature enters and the trigger goes on the stack, not when you cast the spell, so you read the board a step later and lock in the line that actually matters against what your opponent has committed. That flexibility is bought with a color pair that has never lacked for two-power three-drops, which keeps the rate honest. The Powerstone mode is where the design shows its hand, since colorless mana walled off from nonartifact spells is a deliberately fenced-in ramp: it accelerates a machine-building deck without leaking into generically busted acceleration. As a creature, this is a modular utility piece rather than a threat, the kind of card that earns its slot in a deck with enough moving parts to make each of the three lines relevant across a game rather than one built to abuse a single mode.