So. Optimus Prime's awesome axe.
In the beginning I was going with a two sided blade, which worked but wasn't really a nod to anything. However, I searched for a few image results to work off of and I got this:
As you can see, I based the axe blade's shape almost entirely on the old G1 axe, and kept the glowing orange, although now it doesn't cover the whole axe.
My axe is designed to fold up, and the handle can extend or retract for two handed or one handed grip, and can reach up to six feet away from Optimus.
When Optimus gets really angry, he can warm the edge of the axe blade up, to help him cut through metal easier.
Be aware that this is not by any means the final design for the axe, which I expect will go through a few more changes before debuting in Scene 3.