Spark Elemental [Premium Deck Series: Fire and Lightning]

Trample, haste (This creature can deal excess combat damage to the player or planeswalker it’s attacking. This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Spark Elemental.

Vulshok shamans could never keep them alive for more than a few seconds, yet those few seconds seemed to be enough.