Yoshin is an elf, and despite his world-weary attitude and remarkable age, is only just beginning to explore the field of arcane magic. Elves live while their fate lasts, and many live far longer than Yoshin's seventeen hundred plus years, but what the irascible Yoshin has been up to while lurking on the fringes of elvish society all this time is not something he has so far divulged.His life has extended through a great deal of the history of known Alair, but he appears not to have been particularly impressed with it. It's also far from clear why he's come to be associated with his current companions, nor why he practices the more free-form sorcery instead of the formal wizardry more normal to arcanists of his race.
Time may reveal some of these secrets.