Valley Trader Kitzka:
Will of Antharas is a command stone that Antharas implanted into its mostly powerful subordinates, thus gaining control over their movements.
It is also a tool that maximizes the magic powers of Antharas's Subordinates. If you were to combine it with a Sealed Blood Crystal, you could obtain an item with tremendous magic power. For instance, by using it, you can resurrect multiple people simultaneously!
Will of Antharas can be obtained by hunting the Emerald Horn, Dust Rider, Bleeding Fly, Blackdagger Wing, Shadow Summoner, Spike Slasher, and Muscle Bomber, which can be summoned from the Dragon Vortex in Dragon Valley.
"I'll take the Will."
"And what of the other items?"