I am curious as to what would happen if someone were to play an Emotion Control card with Warhawk as a main player. The whole idea behind Warhawk is that he doesn't negotiate. When Warhawk's opponent plays a Negotiate, it's treated like an Attack 0. When Warhawk plays a Negotiate, it's treated like a Morph. Knowing this, the Emotion Control card says two things which are conflicting in this case.

First it says "treat all attack cards played in this encounter as negotiate cards". In this case, the opponent would be an Attack 0 and Warhawk would be Morph (which would also become Attack 0). So, true to what it says on Warhawk's card, he cannot negotiate. It would still be an attack. However, it also says, "The main players must then attempt to make a deal." This is in conflict to what would happen if both sides actually played Negotiate cards.

So what would happen here? Would the cards be treated as Attack 0 cards? Or would they actually negotiate?

The Warhawk's power supercedes the deal-making aspect of Emotion Control. In the end, Warhawk's third paragraph "use" turns those negotiates into attack 00s, and the encounter proceeds "normally".