I managed to finish it. I only dragged him a little ways out of the cave before I got frustrated and just went onto the next part and then while I was fighting some monsters at the altar he showed up. He never showed up the last time I tried just moving on so maybe just getting him out of the cave made the difference? Or maybe you just have to wait long enough and I didn’t before? Last time I kind of just used the altar right away. This time I ended up fighting a bunch of monsters that took a bit of time to kill.