I've been wanting to play Magus, but this is the only theme I could think of in a restricted 300pt. game. During his afro-wearin' days he was the leader/deity of the Universal Church of Truth. They took anything with a humanoid form into their church which was made up of, you guessed it, humanoid aliens. Hence the Supernova generics.

What BFCs would be good?

U Magus 184
V Badoon Commander 37
+ Entrench 5
R Shiar Soldier 27
R Skrull Infiltraitor 25
R Kree Warrior 22
Total: 300

Exhaustion, Inferno, Krakoa Island and shrunk seem nice. Shrunk would be decent since you have 2 shield characters that can bump up Magus's range while your opponents stay halved. Exhaustion because Magus is indominable and Inferno and Krakoa for the stealthers.

Exhaustion is good, and also Krakoa. I was thinking either OD or Defeated as the third BFC.

Also, in Infinity War, does anyone know which heroes were taken over by their dopplegangers? Thanks.

Reed and Ironman were taken over for sure. It may be best to ask in the comics forum to get a quick answer of the people "taken over" when the hero group split up and the doppelgangers were fighting on earth.