Tarvos the Avenger - This is what Tarvos feels is her true state. She describes it as "the rage Mother gave me to destroy her enemies". That is essentially all that it is, pure anger, pure hatred, the essence of vengeance. When she starts down the steep slope of anger, this is where she is heading - and gladly. Here is where she's the most emotional, although the emotions expressed are predictably violent ones... although sometimes other emotions can slip out. Sorrow, even regret... while it's not likely she'll display those to most people, it could happen. She loves the feeling of this state of mind and she loves being who she is meant to be. She's tightly wound, ready to take offense, ready to crack some skulls, just so that she can slip into the sort of purity of being that following her programming gives her. It's the closest thing to getting high that she'll probably ever get (unless somehow someone sneaks her drugs). When she has succumbed to this state, the only person who can usually talk her out of it is Fidchell. It is possible to distract her with a logic puzzle or some other such pursuit, but only if she has not switched forms.
Tarvos the Corrupted - After being joined with Reiko through their Epitaph PC, Tarvos' mind was split into two notions. One was her original state, the horribly violent creature that she was meant to be, and the other was the calm, rational mind of her human host. Even though she is no longer attached to the Epitaph PC, Tarvos still retains this clarity of mind. Due to the fact that she was dominated and controlled by that mind, the clarity aspect is the stronger of her bipolar state and she stays within it the most. She is calm, quiet, and slightly reserved - possibly even pleasant to be around. Smart as a whip and logical to a fault, she presents herself as educated and refined. She's quite critical, however, and her opinions can be quite scathing. She does not tolerate rudeness or boorishness, and tends to lash out against these things. She carries over an appreciation for logic and mentally challenging tasks, with which she'll usually fill her time when not smashing up the neighbourhood.
The Sum of Her Parts - That eternal rage is still burning beneath her stoic expression, and thus her temper is extremely short. She gets set off by small things quite frequently, and if the person is lucky will give a warning before taking action to relieve her frustration. That's about the extent of emotion that she tends to give off, as while in clarity she usually pushes everything else down as being "counterproductive". If there's a good reason to display that emotion, she may do so, but otherwise, it gets ignored. For the most part, this means that if an emotion does come up, she may not understand it due to rejecting it for so long... which often means she gets upset at the emotion involved and freaks out - with predictable results.
She's a classic sociopath, which essentially means that: she has callous unconcern for the feelings of others; she ignores normal social rules and obligations at her whim; while capable of making acquaintances she has extreme difficulty keeping such relationships going - if she even cares to; she cannot tolerate frustration, and easily slides into aggression or violence when she becomes so; she tends to pin blame for her problems on other people or makes excuses to explain her conflict with the world at large; she is more or less incapable of feeling any sort of guilt for her actions and as a result does not learn from past problems or punishments; tends to be irritated for extended periods of time; and finally will usually end up fighting.
Due to the bipolar nature of her mind, Tarvos has a deep-seated hatred for Reiko, and would take a great deal of pleasure in destroying her permanently. Nothing personal, right? She has more than a fair share of mannerisms picked up from her human host, such as fiddling with her glasses and flicking her hair - but don't point it out or else RAGE. Her opinion on humanity as a whole is quite low, due to various qualities that she considers "weaknesses". People who "have their priorities straight" or are suitably respectful she will tolerate, while those who seem to have surpassed their "weaknesses" she will respect for arbitrary reasons. Her criteria for any of these things are unknown and probably based on her current whim. Apart from this system of judging, she shuns all social and physical contact, rarely going out of her way to speak to people.