What episode does Sasuke first have his Mangekyou Sharingan?
As far as I remember it, Sasuke first used it when he attack the Kage summit. I pretty sure it was the in the the early 200s of Shippuden.
Sasuke unlocks it directly after his battle with Itachi. The first time it's shown is actually at the end of episode 141 in Shippuden. Episodes 170-171 in Shippuden are fillers and don't really count in the story.