First of all, I appreciate wanting to think "out of your role." It's a great mechanical and metal exercise, but it also creates problems with the party. Wouldn't any party where this character joins expect him to be a good defender?
I mean, for example, mid-heroics, 3 damage with the Sanction and Challenge? Seriously? That's not going to prevent any DM from attacking another PC.
Now, the entire build is reminiscent of Thor - like the picture didn't gave a clue. - Was this the reason for the maul? There are better weapon choices, for a defender or striker point of view. I take it was to fit the God of Thunder concept?
Also, Sudden Smite? Was it really the best choice? It appears very weak, from both a crunch or fluff point of view. Maybe you can fit a better feat there. Like getting that Mighty Challenge earlier.
There is also a mistake, that I see on many builds here: Overwhelming Impact affects only melee, not close attacks. I know, it's tempting and an easy mistake to make, but maybe it's why it happens so often.
I can see you trying to go for the "max damage" part of the build, you even have a DPR counter. But the total control part? I doubt it. It will be very hard to pull as a defender. Yet, this may excel as a second defender of a party.
Now, another thing that really itches me about builds with assumptions: they should point them out early. It is a necessary evil that these builds must be built in vacuum, away from game and party structures, as well as adventure and campaign context. But there is a different between vacuum and deep space void. It would be nice that these builds opened with a little box containing assumptions made during construction of the build, giving "weak" points that should be worked with the party and DM. Taking this build for example, it would be something like this:
- Fluid starting wealth;
- The Dungeon Master allows dragonmarks;
- Eberron deities allowed;
And so on.
It wouldn't take much space or time, and would be nice for any readers that want to adapt a build for their specific needs.