For a mythic, I think you can probably do without the "no more than twice per turn" rider. I'd suggest get rid of that and add a to the activation cost instead.

just didn't want to make it too strong, but your suggestion works. Thanks.

Is Bosh, Iron Golem not cool enough?

Nothing wrong with Bosh at all, he just doesn't fit the concept/theme of this guy.

The dwarves use magic in their construction, including bound elementals. This is one of those elementals retasked for combat.

_Time Spiral_came out five years before this. That was the set that finally completed the removal of direct damage/ping from blue to red with Prodigal Pyromancer. Blue doesn't get the activated ability.