ANother question then.
Orderbringer is dispelling longsword. Dispeling works as targeted dispel magic on attack 3/day. The question is: can I attack the spell surrounding finnian instead of Finnian in person? It wouldn't then affect all his spells and items, but also wouldn't zap Vorian as he could attack without steping too close to Finnian. Orderbringer might get zapped but is magical weapon and shouldnt' break from small amount of damage.
If that is not possible, I'll think of something else probably entangling whole area or raise wall of stone around finnian