Hello to anyone that is reading this, I would like to start off by saying that I apologize for it not being colored and for it using the original concept art by Kienan Lafferty, but I wanted to keep the original form on the piece and for color I was in pain from Carpal Tunnel and did not want to continue much longer.
I hope you enjoy it and when I am not in pain I might make some pieces from other angles. 
Kilobytten5 votesI've thought of this concept before, and heavily support it. I really ought to have another go at this. Here's some of my ideas to add to the thread:
DerpyUrfgot1 votesI love the amount of thought you put into a lot of things, the only thing I disagree with at least just on a personal level is as you can see I put "Little Boy", a nuclear bomb, on his back and I think it's a cool concept.
I love the idea of the sapling as a pilot and might implement that into the next design because as you can see I have already made them look like little pilots with helmets, its supposed to be the same helmet as the one on his arm.
The color scheme for this was supposed to be light grey and orange with red, blue, and purple/green contrast to make the orange stand out as a magma like color and it can be seen in some of the hollow parts of the body.
I plan on re-doing his waist because I made it a bit too far to the left.
One last thing is as I stated earlier, there is a face on his arm it is just now a helmet.
Thanks for the support and the feedback, some of this is definitely going to be implemented in the next version, keep updating me with your feedback and I will continue to respond as fast as I can!
DerpyUrfgot1 votesLots of Pipes and Exhausts.
DerpyUrfgot1 votesHis Chin is a cage and so is the harp, behind them is some kind of firey magma and it can also be seen all over the image and is for the most part what is causing the steam.
Keagn1 votesVery interesting, this and the lines of MattCom's CLG Maokai would make an excellent skin ^_^
DerpyUrfgot1 votesThanks for the support, be sure to share your ideas and feedback before the next version comes out.
Keagn1 votesIt depends if you're aiming for Mecha, or Junkyard. Since you said Mecha, I'll advise you to the aim near the following points:
-Keep it streamline. Mecha skins are known for their mechanical elegance, (and off blueish color with red/orange highlights). -Have a clear cut design. The pipes and junk bits are neat and all, but they don't read Mecha. Mecha are far better thought out than junkyard, or even Battlecast skins.
Hope these tips help :D
DerpyUrfgot1 votesIt began as a battlecast so I might head back towards that, thank you for the feedback.
Keagn1 votesNo problem ;) , excited to see how this works out :D
Kilobytten1 votesread this and it made me think:
Why not put a piston on his left arm? So the idea is that when he punches, the piston activates on impact to give a "double punch" and make the hit harder. So he pulverizes his enemies through piston punching.
This would go well with his Q, when he slams his fist into the ground, he could pulverize the ground. I can hear a metallic sound then a BOOM. :D
I also agree with this, streamlining it would be good since difference between "mecha" and "junkyard".
Resonat1 votesMechakai?
DerpyUrfgot1 votesClever. 
Resonat1 votesClever.
Also, thought of having a desk lamp hanging off his back? A lantern doesn't really fit with the mecha theme in my eyes, since a lantern is a bit of a downgrade. So put a desk-lamp that hangs off his back or something! Maybe a lightbulb on a rope? ;D
DerpyUrfgot1 votesNo to the desk lamp, it's the bomb Little boy which was made by Robert Oppenheimer, which works considering his name is the inspiration for HeimerDinger along with one other person.