Dual Wield

[Darkstride]

Actually, something like a "parrying dagger" could be used. They were real things used in the Middle Ages instead of a shield. Not dual-wielding in the sense of using it to attack, it's a defense weapon. You don't attack with it, but deflect enemy attacks.

Parrying Dagger

I'm aware of what a parrying dagger is, however the OP specifically spoke of dealing more damage with a second weapon rather than using it defensively. As for Gladiator/Paladin, which was also mentioned in the OP, a shield is more thematically appropriate. They are intended to be able to withstand blows, eat the damage and survive rather than being evasive.