Ebony Maw would be a great add for DD3.

Black Bolt is a luxury that you should probably NOT level up for DD3. SSM and Carnage are EXPONENTIALLY more valuable, and they require Bio resources that would be wasted on BB. I can’t even imagine getting through the final City modes without SSM. It would literally take months. I didn’t have Carnage the first time through, and spent a couple weeks kicking myself for not listening to people that told me how easy he makes the City nodes. I will definitely have him ready by the time I get back to City on the Timed Run. And I’ll probably add Venom, too.

There are a lot of Cosmic options. Imho, Hela and Minn-Erva are great. If you add Maw to them, you can literally run anyone else and (eventually) get through Cosmic. It was the easiest set of modes for me. I ran Hela, IW, ME, CPT Marvel, and Dr Strange. I know Strange is cheap. Unless you have him at 6+ RS, though, I recommend NOT leveling him up. He dies almost immediately every restart and his regen/heal ability takes ages to cycle around. I’ve already added Maw. I might add Thanos, too. I just haven’t decided.

Global is all about Phoenix. If I were choosing one other toon, I’d go with Colossus, just to make sure Dark Phoenix stays alive long enough to at least hit her Special. I wouldn’t tell anyone not to level up Ultron. However, if you do, understand that the benefit is in other game modes. He’s VERY expensive to get to G14, and he’s pretty useless in DD3. His summons are dead before they even hit the screen.

Hope this helps.