I don't care about leaving a legacy. He's a Gold Magister, the college that basically specializes in researching weird magical substances. Hardly another pair of hands.
Also please clarify the risks. That entails a ton of things and you might have made a connection that I didn't.
One of the problems with Johann is that he is a gold wizard trying to play a grey wizards game. And he is doing a fairly well job at it. That should raise some red flags.
In fact he has has so many red flags everytime I see him speak can imagine red flags pouring from his mouth.
A Magister does not hide their status without a very good reason. Why did he do it? Why didn't he reveal his status, even in private, once he knew a fellow Magister had taken command of the group?
Another big problem I have with him is that as a Magister he refused to work with a fellow gold journeyman in an active warzone. Maybe he was afraid of getting caught. Maybe he didn't want to show his hand and reveal he knew far more than he should. But the fact he was unwilling to put his fellow gold wizard above his "mission" tells me a lot about his character.
He seems completely focused on his goal and I trust him to do anything in his power to further that goal. Even if would mean screwing us over.
Gold is the color of logic. I believe he is acting logically. We already know one of his goals, the study of skaven tech, but what goal would have him hiding his true strength and distancing himself from his fellow wizards?
He wants to be left alone and I think if he could stir up enough crap to disappear he will. Mathilde does not want any scrutiny on her. She is studying dangerous things with the Liber Mortis and any attention that isn't "look at how good she is doing" is attention she doesn't want.
My belief is to keep that gold snake at arm's length. That way he can't bite us easily and if he goes up in smoke the backlash doesn't get us either.
It is my belief that Johann is a liability. He is too focused on his personal research to be trusted to act in the best interest of K8P and his character traits seem to put his goals and research above healthy relationships.