The one who took Tobi in and instructed him on how to use the Mugen Tsukuyomi genjutsu in chapters 601-607.
But you're implying that Sasuke has Tsukuyomi. My intention is disprove that believe with evidence given of his MS's techniques.
1. An explicit depiction of Sasuke using the ability in his right eye to apply shape to Amaterasu.
2. Bee explains the reasoning for his ability to escape Sasuke's genjutsu.
The only way Sasuke could have obtained Tsukuyomi is if the transplant of Itachi's eyes made his techniques available to use like how Darkrest described it.
Ok, then what's Sasuke's first MS technique, then? He has Amaterasu/Kagutsuchi and Susanoo. What's the last one, then?