Without the iron weakness, etrigan is pretty damn close to being Thor's equal plus he can cast spells and use hellfire. Thor won't be using the iron weakness because he won't know about it. Etrigan also knows the watchtower quite well so he has a home field advantage.
Shade helps with his essentially infinite darkness abilities. He can teleport himself and etrigan in and out of the battlefield in order to tag Thor without Thor being able to answer. He can also take Thor to the darkness dimension and cause him problems there. Thor is enough of a beast that it's close but the trump should win.
MagicC flash trump maxima Vs. Anti Hero: Black Bolt El Kabong Emma Frost Vs. EnoughSaid: Exodus HeyHey Quasar Vs. Loneshot: Annihilus ZeN Dr. Doom (prep) Vs. Jailblazers: Beta Ray Bill TimmyD Thor Vs. Raiderfan: Etrigan trump shade
Flash trump Maxima
Dr. Doom (prep)
I'm going with Thor because I understand that Shade can be a badass at times, but don't you all remember that scan that vapid showed a couple drafts back, where Prometheus took him out with a flashbang grenade or something that explodes with fancy lights. Thor can easily bring down the pain with his lightning bolts, leaving him to fight alone with Etrigan.