[Bug] Iron Man Level resets

So here I was beefing up my Iron man with lots of stuff (probably due to also beefing it with dark items) when I noticed my Iron Man not being able to do damage anymore Then I opened its stats and cried why 140M best hit to 80k average dmg ;_;. Well atleast it's not healing anything...

You have to be careful giving Mr. Iron negatives, they can stack to no end. It's totally possible to get a Mr. Iron that gets negative experience, loses more than 100% xp to the forge, or costs you gold with each creep it kills.

I can see it gaining 0 exp, but gaining negative seems to be a bit much. This deleveled it to level 0 making it completely useless. Even the negative damage has a limit of -100% why not this too?

I agree, towers should not be reduced to level 0 or have an experience amount of less than 0. I filed a ticket to fix this for version 0.9.3 - Prevent towers from gaining negative experience (0000298)