Notable Passives:

You will spend most of your points in your starting Rogue Skill Tree. 
The Twin Blade is the most important passive here, it allows you to use two Melee Weapons at the same time, at the cost of taking slightly increased Damage. When dual-wielding, you will gain 100% bonuses from each Weapon. The Evasion provides a significant Damage Reduction, but only when you are moving. Since you are using two Daggers, the Critical Precision grants you a ton of Critical Strike Chance. The Sapping Strikes are very important early on, as you can use your Detonating Arrow manually to refill your Mana to throw more Traps. The Agility grants you Haste on Hit, which you will have almost permanently. Remaining Passives will boost your Glancing Blow Chance, Dodge, Health, or Dexterity, you should pick them as you see fit. 

Bladedancer Skill Tree (22 Points)

Notable Passives:

In this Passive Tree, you will get even more Chance to receive a Glancing Blow and a bit of Movement Speed. 
After spending 5 points on the Pursuit you will gain 8% Movement Speed. The Cloak of Shadows grants you a lot of Glancing Blow Chance. You can convert your Dodge into more Glancing Blows for a more reliable defensive layer via Apostacy. The Shroud of Dusk grants you Dusk Shrouds when you are Hit. You can opt for the Veil of Night if you often manually use the Detonating Arrow, which can happen at the early stages of progression. 

Notable Passives:

In the final Falconer Skill Tree, you will gain minor bonuses to your Attack Speed, Dodge, Mana Regen, and Damage. 
The Raptor's Wing grants you a chance to gain Haste and improves your Damage if you have that buff active. The Peltast improves your Throwing Speed, which affects your Traps. The Stamina of the Rover slightly improves your Mana Regeneration and Dodge. 

The Marskman Mastery is required to unlock the Detonating Arrow Skill Tree, but the Passives it provides are all centered around using Bows. You can pick a few bonuses during the leveling if you don't have your Daggers yet, and refund them later. The Rogue's signature defensive mechanic is Dodge and Glancing Blows. The Glancing Blow reduces the Damage you take by 35%, and you can recover a bit of Health when you take such a Hit. 

Explosive Trap - when a Trap explodes it will trigger all nearby Traps as well, and cause them to trigger the Detonating Arrow. You will need to Throw many Traps at once to make this interaction work properly. 
The Arrow Traps is a fundamental Notable that makes you trigger the Detonating Arrows. You will also need the Trapas, corresponding conversion nodes, and Clustered Explosives for a total of 5 Traps thrown at once. The Subtle Sabotage and Jelkhor's Blueprint are very helpful in reducing the Mana Costs. The Trap Sprinkler is another powerful tool, it grants a decent chance to create a new Trap upon detonation. If you have good Mana sustain from your Gear you can take the Automated Bombardment to create even more Traps, otherwise, it is not worth it. 

Detonating Arrow - it is your main source of Damage. In this Build, we convert it into a Melee Attack, but since it is triggered by Traps you can essentially use it from a distance. 
The Arcing Blast is very important Notable for your Clear Speed, it adds the Lightning Tendrils to the explosion. The Weak Spot applies the Critical Vulnerability, making it much easier to cap your Critical Strike Chance. The remaining notables are very straightforward, they just boost your damage, which is why additional levels from your Daggers are very useful. 

Net - it is a powerful utility tool. Throwing the Net buffs your DPS for a few seconds and slows and weakens your Enemies. It can also be used to Dodge incoming Skills if you prefer it that way. 
The main reason to use this Skill is the Leading the Hunt and Quick Throws Notables. After using this Skill you will deal 10% More Damage and have a 20% increased Throwing Speed for 6 seconds. Entangled Enemies will also deal less Physical Damage and have 3 stacks of Frailty, which lowers their Damage further. You can use the Bold Throw to remove the backflip or alter the jump behavior via other Notables. 

Smoke Bomb - a very powerful defensive ability. It creates a cloud of smoke that grants you offensive and defensive bonuses, as well as creates Shadow clones every second that mimic your abilities.
The Smoke Blades improves your Melee Damage with every second you stay inside the cloud. The Umbral Assault creates Shadow Clones to boost your Damage output even more. The Moonlight Bomb grants you stacks of Silver Shroud that guarantee Dodging incoming Hits, even if can't Dodge naturally. 

Shift - a very useful Movement Skill that will swiftly move you toward a targeted location, as well as grant useful bonuses while doing so. 
The Shadowslip makes you immune to Damage during the Shift. You will regain Health and Mana thanks to the Swift Recovery, Shadow Recoupation, and Breathing Technique. The Molting will cleanse negative Ailments on you. You will gain a burst of Speed after using the Shift thanks to the Momentum Notable. The Lasting Presence will create a Shadow Clone for a little bit of extra Damage. You can also opt for Consumed by Shadow if you want to cull Bosses at 16% of their Health, but you would have to give up on Healing or Utility. 

Stat priority:

The Jelkhor's Blast Knife is essential for the end-game, but you can level up using a regular Bow, although it will be hard to sustain Mana Costs and Damage will be lower. To improve your Damage you should seek Critical Strikes, Flat Damage for Melee Attacks, and Throwing Speed. Do not get confused by Throwing Damage, it would only apply to Explosive Traps, not your Detonating Arrow. On your Rings, it is essential to lower the Throwing Mana Costs. The sources of Health Leech are quite limited, you can use the Stolen Tithe Relic, Unique Bleeding Heart Amulet, or resort to the Timeline Blessing. At later stages of the game improving your survivability is much more important. You should get as much Health as possible, cap your Critical Strike Avoidance, improve your Dodge and Armour, cover your Resistance, and improve your Endurance a bit. You can also opt for the Ward version, which offers better protection against lethal one-shots, but has worse sustain and requires more Unique Items with good Legendary Potential bonuses. 

1. Health
2. Critical Strike Avoidance
3. Reduced Throwing Mana Cost
4. Flat Melee Damage
5. Critical Strike Chance and Multiplier
6. Throwing Attack Speed  
7. Resistances 
8. Dodge
9. Armor 
10. Movement Speed 

Recommended Unique Items: 

+44 Melee Damage +4% Critical Strike Chance +3 to Level of Detonating Arrow (-6 to -3) Mana Cost for Detonating Arrow Detonating Arrow no longer requires a bow Detonating Arrow's initial projectile is changed to a melee attack that applies an explosive charge to each enemy it hits. Each charge explodes after the same duration that an arrow from Detonating Arrow would, and the explosion deals the same damage. Detonating Arrow scales with melee damage instead of bow damage +(48 to 65) Melee Damage for Detonating Arrow

Jelkhor's Blast Knife - this Dagger grants you insane amounts of Damage for the Detonating Arrow and can remove the Mana Cost completely if you use two of them, but it also changes your Arrow into a Melee Attack. It will still be triggered by your Traps. It is a common Unique, you should have no problems adding the additional base Damage or Critical Strike Chance via the Legendary Potential system. 

(5% to 35%) increased Critical Strike Chance +1 to Level of All Skills +(1% to 45%) Physical Resistance +(1% to 45%) Fire Resistance +(1% to 45%) Cold Resistance +(1% to 45%) Lightning Resistance +(1% to 45%) Void Resistance +(1% to 45%) Necrotic Resistance +(1% to 45%) Poison Resistance

Omnis - it is a very convenient Amulet that can grant you up to 315% total Resistances, and boost the level of all your Skills. It makes stacking Health much easier, as you don't need to include that much Resistance on your remaining gear. It can be challenging to find a well-rolled one, even more so with a good Legendary Potential. 

(5% to 15%) increased Melee Attack Speed (5% to 15%) increased Throwing Attack Speed (35% to 25%) less Health Regen (5% to 9%) of Damage Leeched as Health You are inflicted with bleed when you cast a spell

Bleeding Heart - at first, this Amulet is a great option to use. It will boost your Throwing Speed and grant you Leech which is very important for your sustain. It is a common Unique, so it is easy to get one with good Legendary Potential. 

Idols:

You can obtain a great amount of Health with your Stout Lagonian Idols, which can also grant Resistance or Armor. If you prefer to get more Damage, look for Crit Multiplier while Dual Wielding, Armor Shred Chance, Throwing Speed for Explosive Traps, or some increases to your Damage. 

Recommended Blessings:

• The Black Sun: the Throwing Health Leech available here is not that great, but it is better than not having any at all. You can also pick lacking Resistance, improve your Leech Rate, or get plenty of Critical Strike Chance or Multiplier.  
• The Age of Winter: this Blessing may be the only source of increased Armour for this Build, but you can also choose the Physical or Cold Resistance if you need them more. 
• Spirits of Fire: here you can pick Fire Resistance, Armor, Dodge, or Endurance, depending on what you currently need the most. The Frailty on Hit is also a good option as you will apply max stacks nearly instantly on any Enemy you encounter. 
• Reign of Dragons: the Melee Health Leech is another good option to improve your sustain. You can also take the Poison, Necrotic, or All Resistances bonus. Crit Avoidance is also very important if you don't have it capped yet. 
• Ending the Storm: you will have 3 options here, all related to Lightning, but you should aim for the Lightning Resistance Shred to significantly improve your Damage against tanky Enemies. 

END NOTE

This is the release version of our Detonate Arrow Trap Marskman Build for Last Epoch, which uses Traps to trigger multiple detonating Arrows at once. We had amazing results with the final form of this Build, and we can attest you won't be disappointed with it. If you enjoy high bursts of damage and don't like to worry about mana management, you have to try out this Build! Future Patches can change the performance of this Build, we will keep our eyes on it and update this guide accordingly to the game's growth.