No emotions, no morals, not after power, no boasting or arrogance, aquisition of wealth is irrelevant, no addictions to vices and/or pleasures, any trace of humanity completely eradicated, this kind of evil is perhaps the most deadly. Even more, the targets are killed so fast that by the time the bodies are found it way to too late to even begin to comprehend where the killer went.
So Alexia only really pays attention to her relationship with the PC, as she logically concludes she needs his/her help to seal the Irenicus contract. All the NPC's she could care less about, and only monitors them for potential threats. So her having no banters with the NPC's (except for maybe some lethal conflicts)
would fit her personality. She might have several talks with the PC (getting info on Irenicus, tactical advice, etc.) and interject something when a big party decision is being made, but is not going to say much else.
Perhaps Alexia should be like Saerileth in that if she is kicked out of the party she is gone for good. She has a MAJOR contract to fulfill and doesn't have time to wait around at the PC's leisure.
As an ultra elite assassin with few if any peers Alexia should have some awesome custom items that she has aquired in her career. A +5 short sword with a double poison rate maybe? Or perhaps leather armor
that boosts all thieving skills massively and has very low AC? I think she should have boots of speed at the very least.
Anyway, I'm very excited about this mod and will post more ramblings as they come.