Which heroes don't have a promo?

Having not played Tactics (other than one brief game at the London meet when it was still in playtesting), I was only aware that there was some version of Omnitron in it who had a rather larger miniature than anyone else ;).

Mmmm...could you imagine how delicious Omni-π would be? Just keeps reforming himself until he gets it just right!

I would love a promo where Omnitron X thinks he's a human named "Nimo Ront"

Power:

Greetings!

Make another player feel good.

We CAN have that promo! We just need to employ my Nobel-prize winning process, reverse fossilization!