This guy here: Somehow after his staged death who was only a double and he escaped his verse somehow and ended up in Naruto verse? Complete with his ingenious mind and his Geass!
He does fit the special eye motiff of Naruto:P
His Geass ability would be really helpful, but I dont think Lelouch would last that long considering that he lacks body strength and endurance.
Then again, he can always use his Geass to control a powerful person/being from the Naruto verse and he'll stay safe.....lol so I guess I'm on the fence :P
I for one think Lelouch might be bored and/or tired of playing King/boss/conqueror so i think he would take more interest in ninjutsu and chakra so he might control a powerful ninja to be his teacher and with his brain and knowledge of all our science he could rise to become one of the most powerful shinobi in naruto verse though he wouldn't be interested in physical battles!
Geass is not genjutsu, there are many types with many different effects such as slowing down and/or stopping experience/perception of time or precog, memory altering, mind reading, transfer consciousness so i guess ninjutsu could replicate these effects but it would take a lot of effort/knowledge/skills and probably bloodline (don't know the case of ino's but itachi's time perception genjutsu is bloodline limit)
He takes the verse by storm. Hell wouldnt be surprised if he managed to ean the title of Hokage! Lelouch is a bawss, after all