I think part of the reason Juno gravitates toward Ramses is that he’s dangerous in the true villain manner in that he talks just enough sense to draw you in. Ramses is directly calling issues out and that’s exactly what Juno wants to hear.
Ramses does see the corruption and hypocrisy of Hyperion City and does directly call it out as something he wants to change, something that we know Juno is desperate to do.
Also, from what I can gather based on their interactions, Ramses seems to be negging Juno, complimenting him in that odd, vaguely insulting way. Take their very first meeting:
“No, you’re not some selfless. But you do act selflessly.”
He goes to say that Juno couldn’t be a selfless hero because heroes risk things of value, and Juno only risks his life, which he doesn’t think is valuable. It’s an awful thing to say, but it’s effective manipulation because it’s true. Ramses is feeding into Juno’s self-loathing by disguising his put-downs as a desire to help fix Juno. We’ve also just seen in general that Juno is predictable and easy to manipulate. Poor Juno.
All this to say, Ramses is purposefully drawing Juno into his web. Even as Juno appears to be irritated, he’s very starting to admire and respect Ramses. Ramses, on his end, is grooming Juno to being his fall guy, his second-in-command, his eyes and ears. The narrative draws parallels between Ramses and Nureyev, but I wouldn’t be surprised if Ramses plays a role in the story more like Mag.