Again, focusing on one core element of the character - in this case, the life-support suit - I redesigned Tony in the following way.
I've always been somewhat perplexed by Tony's decision to always highlight the very thing keeping him alive - his arc reactor chestpiece - by making it all see-through and glowy. Wouldn't anyone with the slightest bit of knowledge about Tony and his condition aim a dirty big laser gun straight it and blast it to bits? I love Iron Man, but I also find it difficult to make the 'magnet in my heart' to 'powered laser blasting robot suit' jump. So, as you can guess I changed a few things.
In my head, Tony didn't get shrapnel lodged in his heart, but in his spine, effectively paralyzing the bottom half of his body and severely limiting the movement of his chest and arms. While in captivity, instead of building an arc reactor to power a magnet, he'd use it to power a crude but highly powerful body brace, capable of moving his body for him, as well as granting him super-human strength (this kind of thing is not that far from reality). Having returned home, I imagine he'd develope
some kind of nanite technology to cure his paralysis more effectively, but work on the robotic exoskeleton suit, incorporating booster rockets, repulsors, etc.
So that's it, my redesigned Avengers are complete! Here's a group shot. Now, to submit these all off to Project: Rooftop (my hopes shall never dwindle). Thanks for reading!