Use high-damage weapons with armor-piercing or explosive output
Focus fire on Klaus’s weak points when they are exposed
Keep moving to avoid his melee and ranged attacks
Use stun, freeze, or crowd-control effects to create openings
Destroy any supporting enemies first so you can concentrate on Klaus
Stay at medium range unless you have a clear burst window
Save your strongest ammo, scorestreaks, or special abilities for his vulnerable phases
Aim for critical hits consistently instead of spraying damage
Reposition immediately after he charges or slams
Coordinate with teammates to stagger damage and keep pressure on him