Caihnmer

Caihnmer was a founding adventurer of the Adventurers' Guild. He was known for working alone, taking quests that sent him far afield and that didn't have a hard time limit. He would be away from Stonespire for months at a time and seemingly appear out of nowhere to turn in his quests at the Guild, and submit his maps, sketches, and notes. The first Guild omnibus was written by Caihnmer and subsequent collections were also mostly composed of his updates.
Occasionally, when he was in the area, an advisor for an under-experienced party would try to convince him to help complete a quest they were having difficulty with. Caihnmer would always refuse at first, saying that it was "uncomfortable and distasteful" before relenting on the condition that someone, namely the party's advisor, or someones, the party themselves, must do something in return. Caihnmer would never say what he wanted them to do but promised to make sure it was something they would also instantly refuse while obviously staring at any females before stating the number of months, weeks, days, hours, and minutes since the last request with a smirk. If their advisor was not the one agreeing to Caihnmer's condition on behalf of the party, he would be relentless on the quest, making the party do most of the work. He would frequently disappear, only to come back to save them from some deadly danger or simply outpace them and be relaxing at camp when they found him. If the party accepted his condition directly, he would have a lot more compassion for their struggles and would take on the role of instructor. In both cases, he would randomly ruminate aloud vaguely about the sorts of things he might request in exchange for his service specifically to make them uneasy.
After the completion of the quest, he'd leave the party to their own devices to turn it in at the Guild with a reminder that he'd be claiming his compensation soon. He would usually reappear during their celebratory dinner, which he would ensure was more lavish than usual. He would be well dressed and showing off in tasteful ways. He'd comment that their little celebration would be a good warm-up for the "after party." While the adventurers he helped and their advisor are cautious around him, waiting for whatever demise he'd planned for them, he would be enjoying himself and gregarious with everyone else in the room. Eventually, everyone would realize he wasn't there anymore and they'd left the adventurers with the bill. It would be months before he'd reappear to turn in a completed quest like it was any other day.
Many years later he no longer came to the Guild and was thought killed or died of old age despite his claims of being part elven. There was a young advisor who was enamored with Caihnmer, having convinced him to help her adventurers many times. She waited several years for him to reappear. The day she gave up waiting, she never came back to work. Every few years someone returns to the Guild with claims they met adventurers with descriptions that match Caihnmer and the advisor.