Satya, Aetherflux Genius
{1}{U}{R}{W}Legendary Creature — Human Artificer
Menace, haste Whenever Satya attacks, create a tapped and attacking token that's a copy of up to one other target nontoken creature you control. You get {E}{E} (two energy counters). At the beginning of the next end step, sacrifice that token unless you pay an amount of {E} equal to its mana value.