lmao you don't just subconsciously activate a Mangekyou jutsu unless it's rigged. he chose to activate amat just like he chose to use susanoo, gen and enton.
Itachi passed his Amaterasu onto Sasuke in an attempt to kill Obito, that was in no way Sasuke. But, after fighting Itachi and gaining his own Mangekyou, Sasuke now had an idea of what jutsu he could use.
of course not. cause in this case he's role is to capture alive not kill, which unfortunately his MS jutsus is aimed for killing.
sasuke knew he had it cause he even said the name of it while using it and if memory serves me right, he used the mangekyou gen before this fight to get intel. and yes, itachi did script amaterasu in him to kill obito. that's what i was referring to when i said rigged.
