Grimalda. Clearly, she is so angry she has transcended anger into true and utter chill, waiting for her moment to yarp-yarp-yarp extensively. Or Lotara, as others have suggested, for maximum giggles.
While the MajorKill stuff has been a change of pace, I have to say that I'm looking forwards to more Baldermort content, and especially your reactions to Baldermort's three-part series on Rogal Dorn or his excellent video on Krieg - your commentary on his videos is often fantastic, and it's probably one of his absolute best.
Can you do more Mandaloregaming reviews? He does a ton of Warhammer games, but he also does plenty of other stuff that is both hilarious and entertaining. Like his Space Station 13 review :)
I got this vibe that Majorkill is a Emperor basher, no wonder he hates Arch so very much. Bold of him to assume the Emperor wanted the Age of Strife, he merely rolled with the punches. The Emperor is a very reactionary character, if you think about it.