Imbue Energy: Harpoon is a mutant with the superhuman power to transform longitudinal objects into various unknown forms of energy. He can imbue any such object with this energy, but the amount of energy varies with the size of the object. Harpoon must throw the object in order to transform it into energy. By throwing it, he can also charge the object with energy without actually transforming it to energy. Depending on the form of energy with which he imbues them, Harpoon's weapons can stun, paralyse, kill, explode, or disintegrate a living victim or inanimate target.
Spears: Harpoon's weapon of choice is a 5 feet long Harpoon with a barbed head.
Body Armour: Harpoon's body suit provides some protection from physical and energy attacks.
You gotta be kidding me if you think this mutant can take out Namor.
Namor can absorb energy to certain levels, and has a considerable level of durability/invulnerability.
This "Harpoon" is just a Gambit with slightly more versatility, seeing Namor took blasts from Presence, a being who's a living nuclear reactor, he's gonna punk this little mutant and show him why IMPERIUS REX.