They do it for the husk of the pit with embalming orbs and crux. Why not for everything else? I would upgrade the stranger's rifle and psi tempest (sorry huge pulse rifle fan) With the armor-weapon core idea you can only ascend it to the next level of gear(common to uncommon), ( uncommon to rare), (rare to legendary). However you'll still need the etheric light to ascend the legendary to max defense or attack. Edit 1: Oh and you'll be able to reforge it when it gets to legendary. Plus some stats in the weapons will increase as the weapon progresses in evolution.