Well, yes, he's a war criminal, but-- [...He moves one hand away from his face, pauses, and returns it. Alright, the "he's actually very supportive and thorough and brilliant and has changed his ways" argument does not seem right when Minimus tries to move it out of his head. Ryunosuke does not need the further shock of learning that he and Megatron became close friends, and certainly not the romantic tension present in their later adventures.

He prays that Rodimus or Drift or anyone else from the Lost Light doesn't show up and drop this information.]

I was a prominent lawyer in an important position, so they picked me. Despite my Autobot leanings, I was the enforcer of the Code of Interplanetary Conduct - a neutral office. Seeing me arresting war criminals despite their alliance fostered a sense of trust from the organic societies in our galaxy, and if there was any Cybertronian the Galactic Council could trust, it was Ultra Magnus.

[He pauses.] That was...the identity by which I went while I worked there.

But I was well-known, trusted to defend Megatron thoroughly, and remain unclouded by my beliefs.