If you've seen the preview for "Alpha; Omega", you'd know that Megatron has found a way to wield the 'Forge' of Solus Prime. In the preview, Dreadwing is removing what appears to be a tomb lid. Whatever is within that container is something that is likely to be whatever Megatron has on his arm, possibly giving him access to the Forge. Now for the wild speculation: I fear he has found the body of one of the Thirteen. The remains of that member would allow him to exploit a loophole allowing him (technically, the Prime), to activate the Forge, and create that "Dark Saber" we later see him with. My guess is the Minicon, shaping his body either as armor, or using his remains to replace his arm. This particular hypothesis remains entirely unfounded, but the last paragraph I stand stalwart by, until reasonable contradicting evidence is provided. Thoughts? Questions? Rebuttals? Comments?