Trample, haste (If this creature would assign enough damage to its blockers to destroy them, you may have it assign the rest of its damage to defending player or planeswalker. This creature can attack and 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.