this message may be offensive
Headcanon for Remus: when he's feeling very upset, he gets quiet. Like, uncharacteristically quiet. His own thoughts get way too loud sometimes, and that's usually when he needs some physical comfort from someone. That someone is usually Janus.
And if someone had triggered Remus' icky thoughts?
You better believe Janus is on his way to kick some ass.
He won't leave until Remus is resting or taking a nap to recharge after all that draining emotional turmoil. He'll wait, especially since Remus has a huge fear of abandonment. I mean, everyone seems to keep leaving him, and that terrifies him. He's terrified that Janus will leave him too. Janus has to reassure the darker twin that he isn't going anywhere.
THEN, and only then, will Janus go beat someone's sorry ass for hurting the Trash Rat.
Because, while Remus may be a bit weird and inappropriate at times, he also has his own insecurities that he needs reassurance for. And Janus gladly helps him out every time.
SORRY, I JUST LOVE THE IDEA OF SOFT REMUS NEEDING HUGS TO FEEL BETTER.