Characteristics: Int +3, Per +3, Str -3, Sta +1, Pre +3, Com +3, Dex -3, Qui -3
Virtues & Flaws: Baccalaureus, Academic Concentration (Rhetoric), Lone Redcap, Obese, Chaste, Fragile Constituion, Well-Traveled (Free)
Abilities: Artes Liberales 5 (Debate)@, Charm 5 (Debate), Folk Ken 5 (Debate), Guile 5 (Debate), Intrigue 5 (Debate), Latin 5 (Hermetic), Leadership 5 (Debate). Area Lore (local tribunal) 4, Awareness 2 (ambush), Brawl 2 (dodge), Carouse 2 (drink), Code of Hermes 3 (interfering with mundanes), Ride 2 (staying on),Survival 2 (forests)
@ Academic concentration give +3 to rhetoric and -1 to other Artes Liberales.
I've copied Callen's choice of characteristics and debate abilities, but with Baccalaureus giving 90xp to AL and Latin they can be 6 years younger. Academic Concentration is a virtue from A&A p12 which I've only used once before (when making an astrologer NPC) - it gives a slight bonus compared to Puissant AL at the cost of a penalty to all other specialisations. As debate uses AL:Rhetoric, this could just about be worth the cost. Theoretically there may be the odd numerologist or astrologer build that could make good use of this Virtue, but it's a very marginal virtue.
I looked at Savantism, the minor flaw in Grogs - debate uses multiple abilities, so being a savant in a single ability and limited in every other one is bad.
One other idea - Have puissant charm, relic as virtues, and choose pious as your personality flaw. A saint's relic will give you one faith point/day to help boost those rolls, and gives you a bonus to invoking the saint. Pious will give you xp towards devotion in a saint (if you use the rules from The Church). Pray vigorously to your patron saint (hopefully you've chosen a great evangelist or apologist for the faith) for a miracle if you find yourself against terrible odds! Also this means your character is a useful person to take along on adventures where you may be ambushed by something surprising and in need of divine deliverance. I know, this challenge is for a narrow situation but I like to look at angles that make a character more generally playable and interesting to use.