Ziggs,Swain Or Viktor

He isn't a reliable opponent because of his healing, and it makes a lot of skirmishes mid game very frustrating because an opportunity may look good but he actually gained health during the trade (many deaths from what looked like a kill). He also remains relevant in games because he has both hard and soft cc, while still being able to soak damage in fights.

Also very dominant when ahead. His zoning is good because if you are caught by his root, his E amplifies his damage enough to chunk you significantly and force you to back. Any return poke is then healed from his ult, as long as he plays smart with the cooldown on his ult.

Source: Level 7 Swain