There was a moment where the tar-kraken stood upright after Erandur had passed through its skull. For a moment it appeared as though the creature had survived the blow.
For a moment.
In a deafening rupture of space and sound the creature exploded violently, sending rivulets of tar, "gold" fragments. Blinding light cast over the room and melted away the tar to ash, before leaving a coral-like structure which radiated golden dusty particles that floated upwards towards the ceiling.
The creature was gone, banished at the hands of the dragonborn.