Welcome to this Lightless Arbor dungeon guide of Last Epoch! Today, I will show you the mechanics of both bosses in the Lightless Arbor dungeon with this Last Epoch guide. I will encompass fundamental principles to enhance your success, irrespective of the dungeon tier you’re tackling.

Lightless Arbor is known for dropping Unique Mountain items, collectively known as the Mountain Set. Items like Peak, Foot, Face, and Core of the Mountain are highly sought after and serve as BiS gear for many meta and powerful builds in the current game meta.

About The Dungeon

You’ll need to clear each tier in order to unlock the subsequent one. These tiers are going to have modifiers that increase enemy damage and health as you progress further. In this guide, we’re going to focus on Tier 4.

Tiers 1 through 3 are easy, and you should be able to clear the tiers as your character progresses and reaches higher levels. You may need a meta character or a powerful build to clear this dungeon successfully.

Navigate The First Floor

To progress through the dungeon, focus on locating 2 corners: either the lower left or the upper right. In these corners, you’ll find 2 doors leading to the next floor. Identifying the lower left corner early, marked by a special corner, indicates that the door to the next floor will be along that edge of the map.

Disregard the middle and right sides of the map, focusing solely on running along this edge until you find one door. After finding the first door, assess its modifiers, aiming for the lowest modifiers to enemy damage and health to increase success chances. Proceed to compare the modifiers of the second door before choosing your path forward.

Use The Burning Amber

Upon reaching the next floor, advance until you encounter a root wall. Destroying it grants access to Kindling inside. Approach the Kindling to initiate its burning process, indicated by its health bar increasing until it is full.

Alternatively, use the 'D' button to send your Burning Amber onto the Kindling, accomplishing the same outcome. This method is recommended, especially for dealing with boss mechanics. Locate the door in the pathways and proceed through it.

Bypass Blockades

Identical to the first floor, subsequent floors may feature blockades such as rocks or fallen tree parts. Aim to locate the lower left or upper right corner to proceed and navigate around blockades accordingly.

The doors will always be positioned in these corners, streamlining your search process and reducing your time spent. Upon reaching the upper right corner, continue along the edge, searching for potential openings.

Select The Next Door

After locating a corner, proceed along the edge, keeping an eye out for any potential openings where doors may be located. Assess the modifiers of both doors carefully, prioritizing lower modifiers for increased success chances. After selecting the preferred door, proceed through it to advance to the next floor.

Dungeon Boss Fights

Upon entering the pass-through room before the final bosses, you can interact with an NPC if desired. Although no door is shown on the mini-map, it will always be located in the northern direction. Clicking on it and selecting 'proceed' will bring you to the boss fight, where the battle begins as soon as you enter.

Mountain Beneath Exterior

It's advisable to head to the left side initially. Break the root wall and use Amber to ignite the Kindling. Move to the right side of the map afterward. If your damage output allows, break down the root wall on the right. Wait on the right side for the large AOE attack, which occurs first on the left side.

Time your movement or use traversal skills to dodge the attack. Utilize the 'D' key to manage the Kindling: return it to your character and then send it to the next pile. Dodge falling projectiles while waiting for the next AOE.

Avoid getting stunned, which is common in this encounter. Move to the left side to avoid certain mechanics. Return the Kindling to progress to the next area. If using a ward build, ensure it's replenished or wait for cooldowns.

Mountain Beneath Interior

The next boss encounter begins immediately and includes one-shot mechanics, so stay alert and prioritize safety. Aim to position yourself opposite to the single beam, as it splits and targets your character.

Maneuver around obstacles, dodge spinning orbs, and approach the boss cautiously to avoid the impending AOE attack. Successfully navigating these mechanics is essential for clearing Tier 4. Clearing Tier 4 offers advantages, including unique item drops exclusive to this difficulty level.

If you're not seeking these specific items, consider farming a lower difficulty level for easier gameplay. Despite potentially lower drop rates for other items, the lower difficulty modifier makes progression smoother.

Vault Of Uncertain Fate

After acquiring the Vault of Uncertain Fate, another entrance will appear, not shown on the mini-map. It leads to additional chests beyond the dungeon, which you can accept or decline. You can do this repeatedly until you run out of gold. There's no time limit, but accepting can be costly, so ensure you're prepared to spend the necessary Last Epoch Gold.

These modifiers are applied immediately, and you can continue declining or accepting as desired. The items from these chests are random, although you can influence them with modifiers. Exiting the dungeon leads to the next zone, Corrupted Lake, or you can use the map to navigate elsewhere.