
A few things to take into account:
1. I have enough resources to rank 5 and awaken any tech champion and about 50 tech signatures stones and 50 generic ones.
2. I have yet to explore variants 1, 2 or 3 and have only done as far as 6.1 completion in the story. Act 5 is explored.
3. Ultron and 6* Nebula aren't the best double immune Champs so I would prefer to take up either Sentinel or Darkhawk to fill that role.
4. I know a lot of you will tell me to wait and see what the story is with Hulkbuster but honestly I'd rather get cracking with the content right now and would rather not wait that long. Also I have a 2016 rank 3->4 gem so I could still rank 4 him at any time.
5. I have a maxed 5* Blade and a 5* 4/55 unduped Ghost rider. I like Stark spidey but I don't think he offers that much to my roster since I already have great damage dealers in a 5/65 Corvus, a 5/65 Hyperion and also a 4/55 Sunspot.
6. I don't however have any high ranked power controlling champs.