Okay, let's try and shake things up a bit, and not just discuss a blank slate beyond "powerful mage/templar"
Instead I'll pose two scenarios, two different circumstances entirely, and we can try and discuss it.
1.) A mage in the isolationist was fully trained in the Circle and is a skilled practitioner of the school of entropy while there but after the events of Asunder ended up among the rebel mages. When Tevinter agents tried convincing him that allowing Alexius in was a good idea, he decided to get out of Dodge, er, Redcliff and ended up in the hills of the Hinterlands. He set up in a cave and acquainted himself with the local flora and fauna, came to know the surroundings. He observed from a distance when Alexius came, the Inquisition setting up shop and the resolution of the rogue groups in the Hinterlands being brought to heel by the Inquisitor but kept himself separate. He's grown content in this life of solitude
A templar joined the Inquisition after the Conclave exploded and was sent to root out the rogue mages who were hurting everyone in the Hinterlands, and to check if any remained after the Inquisitor went through. He's new to the area but was a Knight-Captain with years of experience before the Nevarran Accord was declared void by Lambert. He finds signs of the above mage and sees he's living peacefully, but the mages were conscripted by the Inquisitor and resolves to bring he mage in peacefully if he can, but by force if necessary.
2.) A mage who trained as a recruit as a Knight-Enchanter but hasn't yet made their spirit blade hilt is skilled at using frost and lightning is hunting in the forest to feed a group of mages on their way to the conclave. He was a dalish first captured by templars in his youth, but has since given up hope of returning to his clan, and barely remembers anything of the Dalish beyond some basic tenants he holds close to his heart. Fiery and short-tempered, he's reluctantly converted into the Chantry during his stay and holds a grudge against the chantry and templars.
A templar recruited by the order after they went rogue but before they started taking red lyrium has separated from his own group on the way to the Conclave and is looking for them. He joined the order out of fear of the mages, having come from Kirkwall and when he hears the word "magic" all he can think of is the Chantry exploding. With barely any training beyond the ability to dispel, he is a master swordsman, highly skilled in the sword/shield.
The two bump into each other and tempers flare.