Magnus will be working on hunting down the Shady Man and associates. He will probably try to capture them, but he's not going to be very good at doing that instead of being lethal - he's bad at preventing himself from using deadly force on a normal day, and some aspects of this (the sneak attack, innocent people being hurt, working at the clinic so seeing the victims upfront) are likely to make him extra angry and volatile. Someone who can keep from from killing, or, alternatively, someone who encourages his temper would be a lot of fun to thread out.

I'm happy to plot anything with anyone! He'll be working with Taako, but we can split them up or do a threeway thread quite easily.

EDIT: I should also mention Magnus works at the clinic! He will probably be lying low seeing as he's not a healer and shouldn't get infected, but I'm happy to thread stuff out with anyone sick. He will carve you ducks and cheer you up.