Question

Who is iron man counterpart

Answer 1

Explanation:

However I would submit that the actual closest DC character to Tony Stark / Ironman is Lex Luthor.

Answer 2

Explanation:

Batman/Bruce Wayne. It could be reasoned that Tony Stark/Iron Man is everything that Marvel believes DC should or could do with Batman/Bruce Wayne. They are essentially the same character. The difference is that Bruce predates Tony and Tony has taken the billionaire/crime-fighter etc. to a higher level.