Horizon Forbidden West - All Melee Pits Guide

You can find 15 Melee Pit Challenges in Horizon: FW. You will need to win all Melee Pit Challenges to fight the Tenakth melee master at the end, which unlocks The Enduring trophy. These challenges can be found across 4 settlements, each containing few, and they serve as tutorials except the last one in each which is a fight agains pit master. Nothing here is missable.

One important note - You need to learn all skills in the Warrior Skill Tree as some skills are needed to even take some of the challenges. Make sure to invest your points in that skill tree first, otherwise you will have to earn skill points by doing different quests, collecting and other stuff, to get enough points. 

You can play them all on Story difficulty, but where is the fun in that, right?

Chainscrape (0:01)
0:44 - Block Breaker
1:41 - Resonator Blast
2:54 - Pit Master Challenge
Scalding Spear (3:42)
4:12 - Warrior’s Wrath
4:44 - Aerial Punisher
5:11 - Pit Master Challenge
The Bulwark (5:33)
6:03 - Jump-Off and Shoot
6:38 - Seek and Strike
7:19 - Sustained Breaker
7:57 - Pit Master Challenge
Thornmarsh (8:53)
9:22 - Destroyer Chain
9:59 - Reap and Clear
10:36 - Energy Surge Chain
11:04 - Power Rush
11:42 - Pit Master Challenge
13:03 - The Enduring quest

Chainscrape

• Block Breaker: Block Breaker Warrior skill needed. Do R1, R1, R2 to pull of Block Breaker Combo
• Resonator Blast: Do R1, R1, R1, R2 until you reveal a weak point, then shoot that point with your arrow  
• Pit Master Challenge: Just spam R1, R1, R1, R2 combo to win easily.

Scalding Spear

• Warrior’s Wrath: R1, R1, R1, R2, hold/release R2, shoot with your arrow.
• Aerial Punisher: R1, R2 and shoot the enemy with your arrow from the air 
• Pit Master Challenge: Just spam R1, R1, R1, R2 combo to win easily.

The Bulwark

• Jump-Off and Shoot: Dodge with circle, then press R1, hold/release R2 and shoot the enemy with your arrow from the air or when you land, quickly.
• Seek and Strike: Press R1, then pull left stick up and hold/release R2 and press R2 again to land strike on the second enemy as you fall.
• Sustained Breaker: Press R1, R1, R2, hold/release R1, hold/release R2, shoot with arrow.
• Pit Master Challenge: Just spam R1, R1, R1, R2 combo to win easily. You can also try combos from pits here. 

Thornmarsh

• Destroyer Chain: Hold/release R2, R1, pause (when white glow appears you need to continue), R1, R1, R1, R1, shoot with arrow 
• Reap and Clear: Press R1, R1, wait for half a second, R1, R1, up with left stick towards enemy, hold/release R1, hold/release R2 
• Energy Surge Chain: Press R1, R1, R1, wait for 2 seconds, hold/release R1, hold/release R2 
• Power Rush: Hold/release R2, hold/release R1, then do R1, R1, R2 and arrow hit. Tutorial hints are confusing here 
• Pit Master Challenge: Just spam R1, R1, R1, R2 combo to win easily. You can also try combos from pits here. 

The Enduring quest

When you complete all above Melee Pit challenges you can now find and challenge the Tenakth melee master (they call her The Enduring). Follow the quest marker, and find her just southeast a bit from the yellow quest marker (sleeping on the floor near a tent).

Use everything you've learned against her to win. When you see he is guarding, after the 2nd guard dodge, otherwise she will hit you with parry. I suggest R1, R1, R1, R2 combos and arrows when you reveal a weak point, plus dodge. Not hard, really. 

When you win, The Enduring trophy is yours.