I just leveled up my nuzleaf in the nuzlocke I started, and I’m pretty sure he’s supposed to learn leaf blade at level 28, not synthesis. Shiftry isn’t supposed to learn leaf blade (From the insurgence wiki). Also, my shiftry on my other save file knew leaf blade, which it learned when it was a nuzleaf. Please send help I need leaf blade in my life.
Not sure what to tell you
Try seeing if the Move Relearner will give you the move?
That’s really weird. Thanks anyways. Also I like the name of your vaporeon.