Hey there, Exiles! Are you ready to step into the shadows with a build that's not just off-meta but also an absolute boss-annihilator? We are here to introduce you to the Poison Seismic Trap Assassin, a build that may not sprint through the progression like Detonate Dead, but boy, does it pack a punch! Especially in the Solo Self-Found Hardcore boss race. 

• Ascendancy
• Passive Tree
• Gear and Gems
• Mapping and Bossing
• Gear Choices
• Flasks and Jewels
• Bandits & Pantheons

PoB Link:

• Mapping: https://pobb.in/efsg87zVT6S4.
• Bossing: https://pobb.in/h62KpjhSwRs0.

↖ Ascendancy

Why Assassin? Simply put, every other ascendancy pales in comparison when it comes to early game damage output. Assassin's Noxious Strike is a game-changer, offering a huge boost in poison chance and duration.

↖ Passive Tree

• Core Aspects: Our tree focuses on damage, attack speed, crit chance and multi, cold damage, life, and importantly, spell suppression.
• Cluster Jewel: We're looking at notables like Durian's Lesson and Blanketed Snow.
• Mastery Choices: Key masteries include projectile speed for bow damage, crit multi against unique enemies, and increased damage per aura affecting us.

↖ Gear and Gems

• Main Links: For Seismic Trap, we go with Advanced, Unbound, Trap Damage, and Deadly Ailments.
• Self-Cast Setup: Exsanguinate is linked with Chain, Unleash, and Faster Casting, providing clear and solid damage.
• Alternate Clear Skill: Blade Vortex is an option but might feel clunky compared to Exsanguinate.
• Bossing Setup: Switch to a Cold Iron Point and two Ming's Hearts for uber damage.

↖ Mapping and Bossing

• Mapping Tree: The core tree is standard, but with the new patch, we're incorporating Battlemage for that sweet Divine Ire synergy.
• Eldritch Battery: Crucial for casting skills using ES, ensuring smooth mana management.
• Bossing Setup: Gear-wise, focus on offensive power. For Seismic Trap, prioritize damage links.
• Skill Gems Shift: In bossing scenarios, change your Divine Ire setup and possibly even your curse application strategy.

↖ Gear Choices

• Weapons: Obliteration is ideal for its Fizz to Chaos conversion. Cold Iron Point boosts damage in boss fights.
• Helmet: Look for physical damage taken as Elemental for mitigation.
• Chest: Sadist Garb is a solid choice for this setup, offering flexibility and potential energy shield benefits.
• Gloves and Boots: Aim for offensive stats like attack speed, poison damage, and evasion.

↖ Flasks and Jewels

• Flasks: Standard setup, but focus on evasion and quartz for dodging.
• Jewels: Opt for dot multi, Global Fizz, poison damage, and life. Pay attention to the implicit mods for extra bonuses.

↖ Bandits & Pantheons

• Bandits: Helping Alira is usually the best choice for the crit multi and resistances.
• Pantheons: Go for Soul of Lunaris and Soul of Shakari for defense.
• Leveling: Start with Spectral Throw or Poisonous Concoction, and transition to your main skills as you progress.

And that's a wrap on the Poison Seismic Trap Assassin build for PoE 3.23! This build is a powerhouse for early game boss killing, and it’s perfect for those looking to dominate in the SSF HC scene or even in Softcore trade for high Uber damage. Remember, folks, this build is all about balancing your clear and bossing capabilities, so tweak it to your playstyle.