Of course it could. Genjutsu is "just" the focusing and manipulation of your chakra in your opponent's brain. This is why Tsukuyomi could kill. Jiraiya explained this, and how to break free, to Naruto way back (mold as much chakra in your head as you can, in a big burst).Originally Posted by Abdula
This is also why I think the Rinnegan's secret is a genjutsu -- each of Pein's six bodies use genjutsu on the other 5, so they can all see what the others see.