The hero suikoden 1. He is the leader of the game, and you play as him in the game.
His father, Teo McDohl, is the most thrustworthy ally to the emperor.
Tir has his main group of friends, which are Gremo, Cleo, Pahn, and Ted.
Gremo is very protective over Tir. He is so protective over Tir, he was willing to give his life up when man eating bugs are unleashed in a room by the Flower Emperor Milich.
Ted is also another friend who cares about Tir. When they are unable to defeat an enemy, he risks his cover of holding a true rune to save Tir by using it infront of people.
Tir McDohl is a rare leader of an rpg because he can be recruited in suikoden 2 also.