Knighted Myr

Adapt and double strike sit at opposite ends of the counter economy, and welding them together is the whole idea here. Adapt is a mana sink that only adds a counter when the creature has none: once the +1/+1 counter is on, activating again does nothing until that counter is somehow removed. The clever wrinkle is the second ability, which keys off counters being placed rather than the adapt keyword specifically. That means the double strike payoff does not care where the counter comes from. On its own, this reads as a one-time trick: adapt once, swing with a doubled clock, then the switch is spent. Where it wakes up is in a counter-manipulation shell. Anything that clears counters and returns them (bounce that resets it to a clean state, a way to move the counter off and back, or simply a second counter source) re-arms the double strike. Proliferate is the natural partner: every proliferate step that lands a counter on this body flips double strike back on, turning unspent effects into repeated doubled damage. The counter does the work twice, growing the 2/2 and lighting the fuse, and the trigger's indifference to the counter's origin is what turns a modest artifact creature into a recurring finisher inside the right engine. Standing alone it is a fair beater with a payoff attached; surrounded by counter tech, it becomes a repeatable damage lever that most opponents will underrate.