Tip overview

Because Ash's basic weapon explodes after a fixed distance, with good spacing she can easily hit Vivian around her Deflector Shield, even damaging both simultaneously. Similarly, the exploding shot means you can easily damage Vivian's ultimate drones

Whenever you're up against a Maeve, your Fireball will be necessary as Maeve is more than able to kill you from a distance. If you're alone with a Maeve and not at low health, you can put up your shield and retreat, or burn her with the fireballs.

Assuming you don't have more important targets, hold your ult for when Vivian uses hers. Tag her with a bit of damage, then ult. Be wary of supports being nearby, or if she's running the Scapegoat card, as either will likely shut down the kill

Vivian has some of the highest sustained DPS in the game, especially with her ult active. If an ally gets hit by Yag's ult, you'll easily be able to shred through her ultimate health to save them.

What seperates good BK players and bad BK players is their timing of their bombs. If you see a noob BK missing all his shots, try to pressure him and kill him. But be careful! Many (noob) BK's will panic and use all of their abilities to kill you.