I think Dok/Task/Doom is really strong. Just Dok/Doom (missiles) is a very strong shell, and honestly, all my teams I would consider to main include Dok/Doom (missiles). Dok with missiles just has great neutral game abilities, damage output, jamming bomb combos, etc. Missiles helps cover the weaker points of his neutral (like dealing with teleports), thus similarly augmenting what he is already great at. It really does give you much more freedom and lets you take more risks.
Personally, I’ve given up on playing one main team, since I can’t really find a character that I just think is absolutely perfect with the Dok/Doom shell that I can connect with. I really like playing Strange and he turns the Dok/Doom shell into a devastating counter pick team… but it’s very matchup specific. I like playing Magneto too and he covers a lot of matchups that the Strange team just wouldn’t work well against should Dok die. But even then, I really don’t have much of an answer to Super Skrull, Hawkeye, and Strider, and whenever I face a team with more than one of those characters, it’s a pain. Point Doom can deal with Skrull nicely, but getting Doom out before Skrull gets in is a challenge. I think Dok/missiles can deal with Hawkeye, but I really need to get that first barrier out. I think that matchup is fairly even, but if Dok loses, the rest of my team goes and that’s a big problem, especially against something like Hawkeye/Strider. A good Strider just steamrolls through Dok/missiles, and I can’t really find an answer to it. Oddly enough, my Chun team seems to deal with Strider the best, thanks to Strider’s low health and need to get in, Chun’s good buttons up close, and her upkicks utterly destroying Vajra assist. I would make Chun my main team if I could but… she’s so bad
I’ll keep practicing her anyway because it’s too fun when you can actually get in. My Mags, Strange, and Chun teams are the only ones I actively practice.
I’ve stopped trying Dorm (I just can’t get the hang of him), but I’m still considering Vergil and Viper for Dok/Doom. If I could play Viper really well, I would play Viper/Dok/Doom. There is just too much good stuff on that team and it’s a blast to play when I can actually get hits in with Viper. Vergil is nice too, but I really don’t enjoy playing him as much as the rest of my characters, but I still keep in mind what he can do for the more difficult matchups (like those previously mentioned), though I usually just take the gamble with my Strange team for the HPB into SoV into XF ToD to take out the problem characters. I’ve also messed around with Morrigan, Firebrand, and Chris, but I can’t really get the hang of them either or just like other characters better. I really need to find something for Hawkeye/Strider and to a lesser extent, a good Chris with missiles, though I do need more experience fighting that.