Murky vs Ana
Ana is a good target for Murky. Get into the enemy's backline and zone her out or kill her. Ana can't self heal and her damages take a while to amp up so very easy for Murky to kill. Even if the team focuses you and prevents you from killing Ana that means they aren't using their cooldowns on your team mates. It is also hard for Ana to Heal when you are chasing her as she uses skill shots for her heals.