Kosis In Simulacrium Still Attacking After Death

https://gyazo.com/41ff30248ee172eee77e37edef2fe9a4

As you can see in the GIF, his weapon is permanently on the floor and does damage. Before this it was doing the thrown weapon player tracking whirlwind attack for ~10 seconds after he died. Then the weapon stopped moving as seen in the GIF but it still deals damage.

He spawned, threw his weapon, and it he made some sort of stunned animation possibly (im using spark / lightning damage) as he threw out his weapon. He died shortly after throwing his weapon out. He was alive for 2-5 seconds.