Vallus usually acts mature and self-assured, but easily resorts to calling names or blatantly ignoring the person in question if he's proven wrong and/or otherwise made a fool of. He trusts others easily, but isn't easily fooled or deceived. He holds grudges quite well, and doesn't easily forgive others if his trust is misused. He also doesn't think very far ahead, possibly because he is so caught up in the past. Fear affects him little, since his task and greatest interest is retrieving old history from old ruins and areas people often stay away from.
The Other Side
Inesse seems careless and somewhat sheltered usually, but easily becomes the more mature of the two if her brother is angered or taking offense easily. She relies a lot on him to make decisions and do the talking, but she is fully capable of it herself; she just doesn't want to take the responsibility. She holds a grudge just as well as her brother, but is more wary of strangers than him. Since she serves as an assistant of sorts when they work in old ruins and such, she often walks around the area and investigates while her brother is writing down whatever he finds. She's interested in the past too, but more in the people and less in the events.
Already having experience looking through old scriptures and seeking it,Vallus' magic manifests in his ability to rewind time in lesser contexts. This allows him to restore damage done to old scripts and books up to 100 years back, though he can't rewind major events that cause major changes in history. His task is writing down what has passed, rather than change it. Depending on his own fatigue, he can also rewind time for small areas of bodies, be it his own or his friends'. This allows him to "heal" damage, only that he returns the wounded area to an earlier state of existence.
With similar experience as her brother, Inesse's magic also is of a time-based nature. She is capable of scrying back into the past, to see people who lived then. However, she can only see still images, and hears nothing of what was said or done. This, naturally, makes it very hard for her to actually get an idea of what happened, because of the infinite moments that happened in the past, very few show anything right when something major happened, and she can only do this a few times in short sequence without getting overwhelmed by a terrible dizziness.