A lot of the modelling work has already been done for numerous Marvel characters.
You can find them at deviantart.com if you search "xelandis marvel" or "marvel xps"
They mostly just need to be posed and saved as a stl file.
I'm hoping the thingiverse community can work together to grow the Marvel Crisis Protocol collection of figures and accessories.

I printed the Sentinel at 125mm tall to represent a 20 foot tall Mark II.
My printer is currently having some extrusion issues so the prototype isn't super clean.
I'll try again after I swap out some parts.
If you are able to make a good print of this model I'd appreciate it if you could post your results.

I followed a lead from https://www.thingiverse.com/thing:3690328
and found a bunch of sweet Marvel 3D models at deviantart.com
They are in a 3D format called xps.
I found out about an xps tool for Blender here:
https://www.deviantart.com/johnzero7/art/XPS-to-Blender-2-7x-Blender-internal-the-easy-way-489500171
Then I was able to learn how to pose xps files in Blender over a weekend using online tutorials.

Sentinel model found here:
https://www.deviantart.com/xelandis/art/Sentinel-Marvel-Heroes-XNALara-688679276