I would leave it in there for the other to eat and provide any ammonia source for your cycling tank, if I remember correctly its relatively new. Also, he may not even be dead but molting. My scarlet hermit just didn't move for a week until I saw his "dead body" on the bottom of the tank. Most inverts molt within 3-4 days of being in my tank and then have a regular 1-2 times a month molt from what I've noticed so far. He was walking around an hour later. Best advice when it comes to things that molt (crabs and shrimp) is to not panic and leave well enough alone. Even if it is dead there's not really a point to taking it out. I'm not sure what sort of stress it would cause an invert mid molt to handle/harass it. Good luck!