[quote=@Winter Kitten]I'm not sure Bamf would appreciate concealing his mutation even for a mission. Ahaha *cough*[/quote]
Only if it is mission required, probably end up 'palefacing' like nightcrawler did in the opening of X-2.

I think Bamf is the only other her technically trained in Ninjutsu. And just so people know ahead of time, he is not the "lone warrior' type of ninja popularized by the movies/anime. He is the "one of six acting as one" type of ninja. Example for those who do not know. 

Say the mission is simple: Enter the castle, get the document, make it look like the 3rd in command was in on the theft, escape. THe six ninja approach being equally stealthy, but the one who is specalized in freehand climbing walls goes first up the side to the top and lowers down a knotted rope for the others to follow up. Next the archer puts an arrow through a lantern across the courtyard to draw attention to the activity way over there as they move across the rooftop. the six now split into two teams of three, one to get the document, the other  to plant the evidence. Now enters the hidden seventh member of the team: the Kunoichi, a female ninja who's specialization is the social skills needed to be a member of the maids in this target's house for weeks/months/years and will still be after this mission just in case. She 'accidentally' leaves a window open to let some air in for the others to enter and escape from as the 'strongman' holds the 'agile' one as he is swung into the room to plant the false bribe in a out of the way location that would not be too well hidden in a search of the room. Between the two teams the mission is done.
 
If each of the ninja was observed only once by the guards who saw the incident, it would easily be believed that one ninja went up the walls, shot out the lantern then teleported or ran at inhuman speeds in order to be in two different places of the estate seconds apart from each other as bared by the eyewitness testimony of one of the maids. 

Even His form of Ninjutsu is probably vastly different than the Hand members style. Using just regular items, Magnus could easily be fiddling with his cards when -WHOOPS- 52 pick-up as the deck goes everywhere. A highly distracting action that has people looking up at the fiasco as he flicks an ordinary playing card with enough force to cut a carrot in half, a well known card trick of magicians, right across the carotid in a killer paper-cut.