This post was originally planned as an "after-competition-build-report". But I just changed my mind, and decided not to participate, and rather share the project with you.
So here we go :)
On July 1st 2012 the Work in Progress forum announced a new competition:
The Summer Of Heroes Contest
The rules are rather simple:
We want you to show us a hero. That's all.It doesn't matter what you play,
just as long as there is a "heroic" character available, we want to see it.
Despite working on the ATHENA and the female characters, my head immediately went to work and after a few days I had a (IMHO) pretty good idea.
Working title is "Can Opener" :)
It will (hopefully) be a duell diorama depicting a heavy Ork walker (the can) and a special IG hero character (the opener) figthing each other.
As hero I'll have Captain von Schneider from the Dencarian III. schwere Jäger Abteilung (heavy Hunter Det.). These guys are specialized on hunting and destroying the heavy Ork walker of the Stachelnschweinz clan.
For this task they are equipped with experimental body armor power suits and jump packs.
DAY 1
As usual the build began with a raid to the bits box.
The pose I intend is von Schneider on top of the walker, ripping the roof open with a special power fist. 
The other hand will fire a bolter into the opening.
Some minor cutting and glueing.
A Space Marine bolter will the proper weapon for a heavy hunter :) 
DAY 2
I filled the gaps with ProCreate greenstuff and adjusted the pose a bit.
Then it was time to let it rest and cure...
DAY 3
Once the PC was cured I went to the task of creating the body armor.
The idea was to build it like a knights armor and for this I mounted some rods that would hold the armor in place.
After I mounted the rods and the glue was cured I began to fill some areas with PC again. 
This should've served as good mounting platform for the armor... 
DAY 4
Once the PC was cured I cut some thin .5mm plasticcard and mounted it as armor.
YAK!!!
This looked not even remotely to what I wanted!
So I scraped everything back off ...
Luckily nothing really broke, so I went to bed, hoping to have a solution the next day.
DAY 5
Back to the drawing board - literally.
I decided that I would sculpt the armor with PC and then came up with this sketch of the EREBOS XMI Experimental Body Armor.
(Erebos is the Greek god of darkness and shadow) 
I started with the upper arms.
I even tried some ornaments.
Then he got a higher neck guard (also with ornaments) and I added a first power cord. 
DAY 6
Once the upper arms, neck and power cord were cured I sculpted the shoulder armor, tight armor as well as part of the boots.
As you can see I tried to add ornaments or at least rims on the armor. 
and power cords :)
I really LOVE the tube tool - I ordered mine at PK-Pro:
http://www.pk-pro.de/index.php?page=product&info=277
It's really easy to use and those tubes, hoses and cords you can create are so handy! 
DAY 7
Another night of curing has passed.
Now I added the shin armor as well as the armor for the forearm. 
I have to admit he looks a bit Jules Verne-ish, 20k Leagues under the Sea style :) 
But I really like it.
The white disks will be painted as gauges.
Whenever I had any PC left I created some more tubes. 
Oh, and another muzzle flash! This one will be mounted to von Schneiders bolter.
DAY 8
Almost there! I added some hexagon nuts to the arm and knee joins, together with the armor for these areas. Most likely I will try to mount some cogs on top of these nuts.
I also modified a standard SM jump pack and "steampunkified" it a bit.
I also added his head.
This is the standard IG sergeant head, with goggles mounted :) 
Now some curing and then I can work on the Power fist! 
DAY 8
The power fist!
The PF worried me a lot as I had to sculpt it from scratch and it had to fit the style of the ERBEROS. Also I wasn't 100% sure about the posture of the hand in relation to the ripped open roof.
DAY 9
After the power fist was cured I added some more details. Lights on top of the jump pack, 
some more power cords,
and cogs.
I'm quite happy!
I think this will look great on top of the walker, ripping open the roof and firing the bolter inside.
Next update will be the build of "Cut'n'Crush" -the Ork Walker.
