Vorvadoss's Sand Circle

In the earth around the caster, small lines of green flames suddenly ride across the floor to create a circle, with a central large glyph. The flames stay flowing in the wind below you, you sense the power of an Elder God, Vorvadoss granted you a wink of his ability, so therefore you may choose one target within range to assault with a claw of sand. After speaking the mystical phrase "(The Flaming One, Lord of the Universal Spaces, The Troubler of the Sands, Whoeth in the Outer Dark,) ik krijg een fractie van je mysterieuze uitmuntendheid" you rasie your hand and through the circle, a mimic of your hand that is 5ft tall and 10ft wide emerges with huge gruesome nails. The hand is summoned and reaches out toward the target, a large tether of sand connects it to just beyond the flame circle around you. It rapidly advances toward your choice of enemy and slams into it with great force; target makes a WIS saving throw if fail they take 5d4 force damage and are prone;if pass they take 2d4 and go 5ft backwards. You see their true intent for you have consumed a small fraction of their soul through your attack. If you kill the target with this spell, the sand hardens around their corpse and holds their soul there for 1 minute, you alone may speak to the soul.