Ok now my question is with his first ability. if i give the opponents control check -4, can that give my opponent a negative control check, or does it reduce it to 0. For example, my opponent plays a 4 difficulty card. I make the check and his control check gets a -4. He flips over a 2cc card. would his current control be a -2 or would it only reduce it to 0.

2 - 4 = -2

any number may go into the negatives, and there is no minimum listed on the card