Amusingly, in the German text, Nero says basically "Hey, aren't you the one who tamed the Garlean wolf?" But none of the localizations use the word "killed" specifically—bested, defeated, vanquished. Just vague enough to leave that door open for a Days of Our Lives-style comeback. Also amusingly, Nero really makes zero attempt to conceal his identity, save for the mask; he has a very distinctive mode of speaking in the Japanese version and should be immediately recognizable unless the player skipped all the cutscenes.

Y'know, a part of me is not sure if Nero would save Gaius? Not after what he overheard during the Praetorium battles, and some of his earlier dialogue suggests that he wasn't really all that interested in the Legate's cause in the first place. To him, Ultima Weapon was, for the most part, just another bullet point on his "my future's so bright I gotta wear shades" CV (and he does, he literally does). He was angling to outshine everyone—Garlond, Baelsar, the Allagans, Timbuk3... And you know, Ultima Weapon did make a hell of an explosion...

On the other hand, he desperately wanted to be noticed by Gaius (which is a bit of a contradiction to the earlier point? TBH I think the Garlean scenes and characterization in ARR could use a little TLC and workshopping) and what better way to endear yourself to your soon-to-be-ex-boss than by literally pulling the guy out of said hell of an explosion? Anyway, we've seen that not even Nero is immune to the rare surge of altruistic energy.

So I dunno! I know nobody asked but I'm only 50/50 on whether Shadowhunter is actually even Gaius at all. I have my own theories but I guess we'll find out soon enough! My plot sense tends to be...bad. Really bad. So, grain of salt I guess.

(Also in re the Alliance raid... The whole magicite thing gives me super dodgy vibes but I can't quite put my finger on 'em. It reeks of something what oughta not be there. Garleans maybe. I dunno. Again, we'll see!)