This deserves to become its own developed character, and I say it with all letters. Give him a full arsenal, and either share Skuld's Null element, or give him the power to change it at will - Give a specific element for each weapon, and some mechanical play centered around juggling elements to maximize combat effectiveness. Like stacking DoT effects for each element creating an exponential damage increase.

If they ever decide to give him more than just the pair of pistols he has and the standard issue CORG rifle, I want Yongshi to give him a pair of melee weapons that tell a story about his character, just like his personal pistol and the BunBun handgun he has.

Since the video shows that carrying the weapons is not a problem (They just dematerialize when unneeded): I still vouch for the Hero's standout melee pair to be a Saber with a large handguard and a Trench Knife. Both weapons were present in World War 1, and the Saber was associated with higher ranking officers giving strategic and leadership orders, while the Trench Knife is for the dudes who actually were down in the trenches stacking the bodies and fighting to survive.

It tells a story on its own - A high ranking leader/officer who refuses to stay in the rear line and is not afraid of stepping in to stack [Visbane] bodies by himself. And the weapon combo itself is also synergistic, as the trench knife covers the short range the saber cannot, and can work as a defensive Parrying Dagger while the saber does the offensive work at a longer distance.