The Supervisor of the War. He's more than just an observer, however....
Sharp-tongued and a bit of an ass, Voir has no difficulties in maintaining neutrality, as his personality alone would make any potential ally have second thoughts. He hates being disturbed by people more than anything else, and if forced into a conversation, he will only say what is barely needed. This personality makes him a rather unapproachable Supervisor; an unusual case, to say the least.
Being the Supervisor of a once-in-a-century ritual, the Magus world has given Voir with a considerable measure of influence over the investigative, medical, and government affairs of the city-battleground. This helps him greatly in his work on covering up potential damages and casualties caused by the war, maintaining peace in the city while the war takes place.
In terms of magical ability, he specializes in tracking magic as he is able to know the whereabouts of the participants of the war, and their current condition(whether they've been eliminated or not).
The latest of the long line of Supervisors of the fabled Grail war, nothing much is known about Voir except that he is not from the city where the war takes place, but only a representative of tha Magus world to ensure their secrecy from the rest of society.