Before you can participate in the Nadaam, you must pass through Bardam's Mettle and tame a yol.
How to Unlock
The Bardam's Mettle 4-player dungeon is unlocked by the level 65 Main Scenario Quest In the Footsteps of Bardam the Brave.
Garula
Hit the boss to start the battle.
Heave is a large cone attack in front of the boss. Move out of the cone to avoid the attack.
Crumbling Crust hits small circular areas in random locations around the area. Move out of these circles to avoid the attack.
Rush will target a random player with a tether and a line marker. This player needs to move as far away from the boss as possible to minimize the damage from the attack, and other players should stay out of the path of the attack.
Warcry will wake up the untargetable animals around the area, and Earthquake will damage and temporarily stun all players. As soon as the stun wears off, move away from the ongoing animal attacks. At various times, the yamaa (goats) will do line attacks toward random players, the sheep will do circle attacks centered on themselves after running to random players, and the coeurls will do very large cone attacks at random players.
Bardam
In the next boss battle, there is no combat. Instead, you have to avoid getting hit. Those who get hit too many times will be chained with fetters, and if there are too many hits overall, you will have to start the battle over.
First Trial
A Hunter of Bardam pulls everyone toward it, then begins casting Empty Gaze, a gaze attack. You are safe from the gaze attack until the Empty Gaze cast bar becomes full, so keep that in mind when dodging the other attacks. First, the Hunter of Bardam will have a circle attack marker around itself, then a ring attack marker around the edge of the area. Stay outside of the circle attack, then as soon as it disappears, move into the center, while also facing away from the Hunter of Bardam to avoid the gaze attack, which should finish casting around this time.
Afterward, the Hunter of Bardam will start casting Empty Gaze again, and there will be alternating grid line attacks from the spears around the edge of the area. Avoid the line attacks, then turn away from the Hunter of Bardam before the Empty Gaze cast bar becomes full.
Second Trial
Make sure that there is a player standing at each of the towers that appear. After that, the players who are targeted with large donut attacks can stack together near an edge of the area to overlap their donuts, reducing the area of the attack and allowing unmarked players more room to avoid the attack.
Each player is then marked with a marker over their heads, and after a moment, a circle attack marker appears beneath the marked players. The players need to move out of their circles and keep moving, because they will be followed by circle attacks for several more seconds.
After that, the Hunter of Bardam will do an expanding cone attack. Make sure not to stand on the most recent segment of the cone to appear, or just stand behind the Hunter of Bardam to avoid the attack altogether.
Large circle attack markers will appear. Move out of the way of them to avoid damage.
Third Trial
During this trial, there is a looming shadow in the center of the area. To avoid getting hit by its attacks, you need to hide behind the Star Shards that have appeared in the area, making sure that there is a Star Shard between you and the Looming Shadow. However, at the start of this phase, two of the Star Shards will have a circle attack marker centered on themselves, and will disappear. Watch the Star Shards and make sure to hide behind one that does not have a circle attack marker. Soon after you find a safe Star Shard, spears appear around the edge and do a grid of line attacks, so make sure to stand in a safe spot, then make sure you are hiding behind a Star Shard afterward.
Next, there will be a ring attack marker around the edge, and two Warriors of Bardam will both do expanding cone attacks toward the center. Dodge the ring attack and cone attacks. One of the Star Shards will be destroyed by this, so quickly find the one that has not been destroyed, and hide behind it.
Arrive in the Voiceless Muse
As you go toward the final boss, be sure to dodge the large rolling boulders that roll down the path at various points along the way.
Yol
Wind Unbound damages all players and summons wind orbs around the edge. The wind orbs will target random players with line attacks, so be sure to avoid these attacks throughout the battle.
Flutterfall places a marker above players' heads, then drops a circular feather attack on them. Spread apart from other players to avoid overlapping these attacks.
Eye of the Fierce is a gaze attack. Turn your character to face away from the boss to avoid it.
After the boss takes a certain amount of damage, it becomes untargetable and summons a Corspecleaner Eagle. Kill the eagle while watching out for the untargetable Yol to appear at the edge. The Yol will soon attack in a straight line across the platform, so make sure not to be in its path.
After you kill the second Corpsecleaner Eagle, the Yol reappears.
After the Yol's health is below a certain point, you will only be able to attack its Left Wing and Right Wing. At this time, circle attacks will rotate around the edge of the area.
Wingbeat will place a green marker over a player's head. This attack will knock the player back. Marked players should position themselves to avoid getting knocked into the rotating circle attacks.
Throughout this phase, you will also have to dodge line attacks from the wind orbs around the edge, and players with orange markers above their heads should avoid overlapping their Flutterfall attacks.
Completing the Quest
Defeating the boss will complete one of the quest objectives for the Main Scenario Quest In the Footsteps of Bardam the Brave.