Im looking forward to painting lucius too, nice model. However, im not at all enthusiastic about fielding him. For his price he gets no special movement mode, so you need to give him transportation and a squad to enter the transport with. Then you propably have to tool the squad to fit this role, and so we are talking a roughly 400pts unit even in a rhino. A land raider would allow for easier charges, but that'd just be solving a problem with a bigger one
I guess hed perform very well in any combat he can reach, but I'd have to go with a chaos lords better movement even if it means less combat ability. Fielding Lucius does earn you style points though
Lucius can be fielded in any CSM army he can lead. That is limited by his Mark of Slaanesh. Aura of Acquiscense of course overrides tha Lash of Torments -ld ability since no morale check will be taken, but otherwise im not certain of the Lash's ability. Maybe he can participate from within a locked squad he has joined and attack models hes not encaged with?
-Squirreli