Lower your music's volume and listen for sound effects. If you're her target, you might hear her coming. If you aren't, you might be able to save an ally.
In Pursuit is highly effective against her. One or two shots are all it takes to let In Pursuit finish her off. Side note: She might heal while you are using In Pursuit should she have Artful Dodger, Patch Up, and/or Savagery.
In Pursuit checks who is closest with each shot. If you manage to fight him in a 2v1, alternate who is closer or have the person with the highest health stay in front to protect the person in back.
If Barik is hugging his Turrets, use fire bomb. The turrets cannot be moved once deployed, so he will likely abandon them if fire bomb lands on or near them.