I knew I would never have enough souls in a weapon at any one time to have a dominant weapon. It just isn't my skill set or play style. I did hope to eventually get to the first level of controls. I understand that is over an accumulation of collecting souls and not just based upon the souls in the weapon at any one time. Marzzett auto'd with full con I think and probably a train or two left. I just lost interest.
I would think if I had a 15 or 20 soul sword and lost it I would probably cry myself to sleep. But just knowing me and how I am that is beyond the realm of expectation. And like I said, I didn't mind. I also understand that rp affects how you loot. Most folks who kill me take one or two things only. A villager might take my best or 2nd best magical armor and sac it or whatever they hell they do with it to thicken the veil. All good. I will say that 99 percent of my player interactions in this game are positive, and that includes the gear part.
I have not decided how I would treat an unholy. I might barter it back if I was neutral or evil. I almost never play light so I cannot tell you what I would do. I would think an unholy blade should be destroyed :)