The 2.0.1 update added Ares' Exoskeleton, a Summoner drop from Draedon that lets you wield the big guy's cannon arms for yourself. You can even customize how many of each arm you want, so there's nothing stopping you from using 4 Gauss Nukes and calling it a day.
It also currently seems very strong, but I'd advise against using it in Exo Mech refights for now, because it uses the same projectiles as them and causes quite a bit of confusion at times.
