Martin is a 40 year old human wizard with natural dark magic abilities. He is employed as professor for philosophy in London, but secretly works for the Bureau for Supernatural Affairs.
His magic is considered dark and aggressive by most, so he usually uses it only in secret.
He can't do any magic considered "white" or "good".
His tasks are testing, recruiting and teaching supernaturals, getting those gone rogue back in line or hunt them down.
He likes using his magic to convince in subtle ways.