Valley Trader Kitzka:
The Sealed Blood Crystal is formed over time from Antharas's spilled blood.
His blood has lost its magic power, but if you combine it with Will of Antharas, you can still obtain an item with tremendous magic power. Use it, and you will be able to resurrect several people simultaneously.
This Sealed Blood Crystal can be obtained by hunting the Drake Lord, Behemoth Leader, and Dragon Beast inside Antharas' Lair.
"May I take the crystal?"
""Tell me about something else."