Sitheus
From Immwiki
Sitheus prefers srryn, but will take what he can get. If you are not srryn, he will turn you into a srryn, but he is not able to turn you into a live srryn... so as you go on in the faith, you will have body parts turning into necrotized srryn parts, and you will start having your (max)stats changed to be more srryn-y.
sigils are coloured serpents. t3 is the black serpent? (12571/13832)
Contrast his manipulation of undead to Rveyelhi's golemancy (shuddeni have no real problem with his rotting, animated corpses crudely stitched together, but do disdain it as crude; they like the refinement of technique, building a better undead monstrosity, etc)