I don't know. Teshin seems weak. He did briefly side with the Grineer Queens after all. Which wasn't exactly his fault, I know. He has to follow orders. I don't want to follow someone who can be mind controlled by the bad guys. Also, every time I hear his voice I want to buy insurance.
Ballas is scary. I think that's because we don't know a lot about him and he's "new". He did help create the Warframes though, and had reasoning behind each one. It may not have been good reasons, but here we are.
Lotus... augh. She's a genocidal maniac IMO. Tenno, kill this. Tenno, kill that. Assassi