Satya, Aetherflux Genius [Modern Horizons 3 Commander]

Menace, haste
Whenever Satya, Aetherflux Genius attacks, create a tapped and attacking token that's a copy of up to one other target nontoken creature you control. You get EE (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.