First Sinner Boss Guide (How to Beat)
The First Sinner is a tough, fast-paced boss you’ll find locked away in The Slab. This fight is all about reading telegraphs and playing aggressively. The boss uses a mix of teleporting slashes and telegraphed needle attacks to control the arena, but its most dangerous move is its ability to heal itself. Your main job is to stop that heal while surviving the storm of needles.
First Sinner
Location: The Slab
Rewards: Rune Rage Ability
How to Find the First Sinner
Section titled “How to Find the First Sinner”The First Sinner is locked behind a large door deep within The Slab. This isn’t a boss you can just stumble upon; you need to find three specific keys scattered throughout the world to open the door to its room.
- Key of the Apostate
- Key of the Indolent
- Key of the Heretic
Once you have all three keys, you can unlock the door and challenge the boss.
Recommended Loadout
Section titled “Recommended Loadout”This loadout is built for survivability and applying constant pressure to stop the boss’s healing.
- Ability: Silkspear - Great for hitting the boss from a medium distance, especially when it’s starting its heal animation.
- Crest: Reaper Crest - The wide crescent swings make it easier to hit the fast-moving boss and clear out needles.
- Tools:
- Fractured Mask & Magnetite Dice: A great defensive combo. The mask gives you an extra life, and the dice give you a random chance to completely ignore a hit.
- Pollip Pouch & Threefold Pin: This combo lets you throw poisoned pins, applying a damage-over-time effect. It’s perfect for chipping away at the boss’s health while you focus on dodging.
How to Beat First Sinner
Section titled “How to Beat First Sinner”This fight gets faster as it goes on. Learning these core steps is key to winning.
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Read the Silk Lines Every single needle or blade attack is telegraphed by a white silk line or glowing marker that appears a moment before the attack. Your first job is to train your eyes to see these lines and immediately move to a safe spot. Don’t watch the boss, watch the lines.
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Stop the Heal at All Costs Occasionally, the First Sinner will stop and try to bind to heal itself. This is the most critical moment of the fight. You MUST attack it immediately to interrupt the heal. If it succeeds, it will recover health, making the fight much longer and harder.
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Punish the Summoning Animation Your main window to deal damage is while the First Sinner is standing still to summon its next needle attack. It will do a brief binding animation. Use this opening to get in a few quick hits, but don’t get greedy. As soon as the silk lines appear, your priority shifts back to dodging.
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Survive Phase 2 After you deal enough damage, the fight gets faster. The boss will start using its Explosive Runes attack, which fills the arena with circular AoEs. The core strategy doesn’t change: read the telegraphs, stop the heal, and punish the openings. Just do it all a bit faster.
Attack Patterns & Counters
Section titled “Attack Patterns & Counters”We’ve consolidated the different “blade” and “needle” attacks from the notes into one clear list.
The boss scuttles quickly from one end of the arena to the other, slashing multiple times.
Counter: Jump and dash over the boss, then try to hit it from behind as it finishes the animation.
The First Sinner disappears and reappears directly above you, then slices straight down.
Counter: The moment it disappears, dash to the side. It will be vulnerable for a moment when it lands, giving you a chance for a quick hit.
Two telegraphed lines appear in an ‘X’ or cross shape, and needles/blades quickly strike along those paths.
Counter: The safe zones are the diagonal areas not covered by the lines. Stand in a safe quadrant and use the opening to attack if you’re close enough.
Two needles are summoned and shoot horizontally across the arena, usually one high and one low.
Counter: Watch the telegraph lines to see if you need to jump over the low needle or stay on the ground to let the high one pass over you.
A row of needles is summoned above and shoots straight down in a spread pattern.
Counter: The telegraph lines will show gaps between the needles. Find a safe spot between two lines and wait for the attack to pass. This is a good time to attack if the boss is nearby.
The First Sinner stops and attempts to bind, glowing brightly. If the animation completes, it recovers health.
Counter: This is not an attack, it’s a race. The moment you see this animation start, hit the boss as fast as you can to interrupt it.
Only used in Phase 2. Glowing circles appear all over the arena floor and explode after a short delay.
Counter: Keep moving and avoid standing on the glowing circles. Use the safe patches of ground to reposition and attack the boss.
First Sinner Rewards
Section titled “First Sinner Rewards”- Reward: Rune Rage Ability - Defeating the First Sinner grants you this powerful AoE Silk Skill. It allows you to sew “rending runes” onto your enemies, which then detonate for targeted Silk explosions.
First Sinner Lore
Section titled “First Sinner Lore”Ancient Weaver condemned for a transgression lost to time. This one’s husk held a masterful talent, to weave Silk into blazing runes. Throughout my life, I have seen runes woven for many tasks. Was she the first to hone such skills?