Tomorrow at my local hobby shop is a 600 pt silver age no resource tournament. I was thinking about using

Tiamat
Winter soldier ( civil war )
Simon baiz ( prize version )
Metallo

I would have 25 points left over ( due to the 5 points for winter soldier's shape change trait )

Any ideas on changes I should make or things I can add to fill the gap?

Nightwing at 25 points to Outsider Tiamat ...

I will defiantly look into that :3 thanks for the idea~

You can also add Atomica (from Fast Forces) for prob control. She's 25 points.