UN2 you can solo UN1 possible but very very hard UN3 possible but very very hard UN4 possible but very very hard
5-10 in your dreams XD
UN6 is possible too except lots of patience is required.
Yeah saw the ninja cinema of UN6 in the 1st place on the leaderboards and it was a very impressive piece of work, saw another solo UN4. Really entertaining to watch. --- OMG THE ENGLISH LANGUAGE SUCKS!!!!! -- Every subtitle purist ever....