Khan has an easier time taking care of other tanks. Use Fernando's charge to reposition yourself if he happens to be dissing on you, and try to protect your teammates from his ultimate by using your shield.
Fernando isn't the best at killing, but he can certainly pump damage. Working on the point, always fireball and flame groups, and charge into them to get behind them. Use the Scorch legendary to deliver as much damage as possible into groups.
MOVE AS MUCH AS POSSIBLE. If Bomb King lands at least one bomb on you, your pretty much done for. His AOE makes it easy for him to land hits on you. Attack him from the air and flank around him to throw him off.