Sorry, I was just abbreviating "Thrall of Malcanthet," not the Thrallherd or whatever class.
Insidious Corrupter is interesting. You have the Claws of Influence at-will, which is nice, against 4 targets at a time, getting +10 Bluff, Diplomacy, Intimidate, and Sense Motive; give them +/- 10 Perception for a minute; Detect Thoughts and Confuse without a second save; you can give allies an extra action, or force enemies to use theirs; Dominate Monster; or end the effect with a swift compulsion with +Cha DC! And at 10th level, even use the originating effect, Claws of Influence, as a swift action as well. Your spellcasting would be limited to CL 8, or 4th level spells, but those are just supplemental to your class abilities. Even though they're lower-level, your compulsions would have a really high DC.
So I guess you can go full Sorcerer for class abilities; War Weaver for party buffing; Thrall of Malcanthet for sneak attack +3d6, Cha +4, deflection AC of Cha (up to 10), Detect Thoughts, reflect enchantment spells, +8 Bluff, Diplomacy, Intimidate; Insidious Corrupter for the Claws of Influence; or something else entirely.