Every Suikoden game had at least one
Suikoden I: Pesmerga
Suikoden II: Tir if you started from S1 save data, Georg' otherwise
Suikoden III: Technically Thomas is the main character, so take your pick of True Rune holders, or sub in Sasarai
Suikoden IV: Ted
Suikoden V: Richard, Georg', Zerase, Belcoot, Killey, Mathias, and Roy. Lots of OP characters in Suikoden V.

Don't anybody say Mathias doesn't belong the list, or I'll be forced to exact swift and final retribution and discard your loathesome corpse into the sea.