The Arena Guide - Horizon Forbidden West
Ready frostbite warrior bow with frost light arrows and burst fire weapon technique.
As soon as you get near, you have to use the technique two times and then spam the arrow until he gets "Frozen".
If you see that the attack is coming, you need to roll backwards two times.
After applying frozen status, you have to switch to an iron eater shredder gauntlet.
Depending on your weapon stamina alternate between triple shredder and normal shredder attack.
After a few shots, the boss gets knocked down.
As you do more damage, and when he is frozen, switch to bow and focus on the weak points.
As soon as he leaves the knockdown state, you need to activate the valor surge.
Now you can inflict more elemental damage, the goal is to repeat the process as before but quicker freeze him first.
After applying the frozen status, you will need to switch to an iron eater shredder gauntlet.
Depending on your weapon stamina, alternate between triple shredder and normal attack.
Ideally do not get mauled but in the frozen state he is slow, you will do better than me.
After knocking him down again, you have to focus on the weak points.
As soon as he leaves the knockdown state, you have to activate the valor surge.
Think you know what to do now.