This instant card was made for Xenagos, God of Revels players, who want to take their opponents down quickly.
However, that is not the place Unleash Fury could fit. A commander like Zada, Hedron Grinder could also work. This commander allows you to copy Unleash Fury on every other attacking creature on the board, which could be lethal for your opponent.
Basically, think of Unleash Fury as another copy of Temur Battle Rage.