Might want to crack the line coming out of the clutch master cylinder and check for air at that end first, bleed that end. I have ran across clutch master cylinders fail internally after years of moisture collection (condensation) inside pitting or oxydizing the piston walls or hardening the rubber piston cups. Many times any kind of air within the system will rise up to the point of the clutch master. Wouldn't rule that end of the spectrum out, just quite yet. Many Legends owners never maintain the fluid within the clutch system on a normal schedule, if ever at all leaving fluid in the state of breakdown. Rule of thumb in the bike industry is NOT to blead the clutch as you do brakes at the slave cylinder. Gravity bleeding is the way since the bleeder end is cut off for clearence of the driveshaft coupler. No nipple on the slave rules out the second best way to bleed a clutch system which is the use of a Vagula. Bleeding a slave like you do brakes, since the system has a low amount of fluid will leave air in the slave from natural reflex of the piston oring relaxing and drawing air back into the system, even if the pedal is depressed and before the bleeder is closed. In all honestly, my friend, I would open the bleeder, gravity bleed the entire system and refill with fresh fluid. Then bleed the master cylinder at the line. Next if need be, if the shift problem still exists, bleed the system at the slave while holding the pedal, then gravity bleed it once agian for a short spell and replentish the master resivouir with fluid. If the unit still will not shift or shifting issues persist, try replacing the master cylinder with a known good one. Failure of satisfied shifting thereafter.... you will have to pull the clutch cover off and inspect the clutch pack. With heat demands on these clutches, a fiber disc may have 'froze' to a steel plate within the clutch pack, giving the sensation of a master or slave issue that does not exist..... I hope you find this info helpfull... I've seen it all in 30 years of the bike tech industry... nearly all anyway
~ Gimpster ~