Whose are the S+ tier characters but overlooked by many?

I'll raise Sheena.

I'm shocked to find out that many players don't use Sheena in Suikoden 2. Many people assume he is mediocre but he is possibly THE strongest character in the game.

He only need to be around level 45+ to unlock all rune slots, can equip good equipments and shield. Equip Double-Jab, Double Stikes and Fury on him and Rage Orb/Thunder Orb in his sword. Give him a master garb and some fire emblems and an earth shield.

He will be immune to status effects and will comfortably deal 2000+ ( 1000+ x 2) damage per turn without critical.

He is Suikoden 2 version of Richard, unassuming lad who will demolish everything lol.