Some Fernandos know how to chain fireball with their dash ability to deal massive damage to groups; don't group together when trying to fight an aggressive Fernando so he has a harder time picking you off!
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.
Do not hold the fire button when playing as Fernando. Your weapon deals damage over time after each hit.
Tapfire instead, so you can get value out of the DoT and refill your ammo in between shots.