From IvanWiki

Sophos can be great in certain circumstances.

If he is happy with you, you'll get teleported to a different part of the level. It's not like a normal teleport, however, and teleport control will not help. His other great use is granting you a new limb of some nice materials, if you're missing any limbs. He will mostly grant a limb of hardened leather [though with enough intelligence this can hardened to more useful materials like phoenix feather or dragon hide]; but may sometimes grant a limb of arcanite, mithril or even octiron.

If he is angry with you, he will teleport some of your equipment away. In worse case situations, he teleports your limbs.