Once Human SN700 Finale Build: Kill Bosses Without Firing a Shot

The SN700 Finale sniper rifle has a quirk in how it counts the final bullet in its magazine, and that quirk lets you delete bosses in Once Human without ever pulling the trigger. The trick leans on the weapon’s Shrapnel and Reverb passives, a helmet that adds extra hits, and a deviation whose butterflies register as weapon fire. Build it correctly and elites melt while your magazine stays loaded.

Quick answer: Fire until exactly one bullet remains and your Reverb count sits at 3 or 4, keep the rifle in hand, then deploy the Butterfly’s Emissary deviation. Each butterfly hit counts as the last bullet and repeatedly triggers the multi-Shrapnel burst without spending ammo.

How Shrapnel and Reverb work on the SN700 Finale

Standard Shrapnel scatters damage across random separate body parts. The SN700 Finale changes that. Its Shrapnel can strike the body part you aimed at repeatedly, and it no longer excludes hit parts, so every proc concentrates damage where you want it.

A body hit has a 40% chance to trigger Shrapnel. A weakspot hit always triggers it. Every trigger grants one stack of Reverb, up to four. Each stack does three things at once: it adds one more hit part to Shrapnel, cuts recoil by 7%, and raises the damage of the last bullet in the magazine by 5%. At the four-stack ceiling that works out to -28% recoil and +20% last-bullet damage.

The part that makes the whole build possible: once Reverb is at 3 stacks or more, the last bullet’s Shrapnel trigger fires additional times equal to your Reverb count. Reverb clears the moment you reload or switch weapons, so the entire sequence has to happen without either action.

The zero-shot boss kill, step by step

With four Reverb stacks the final shot triggers Shrapnel up to five times. Add the Cage Helmet and that climbs to six. Layer the MP57 Div-Evo’s weakspot bonus on top and a single trigger can land as many as 36 separate damage ticks. You confirm it is working when damage numbers stack up on the boss while your ammo counter stays at one.

Gear that multiplies the Shrapnel hits

Two pieces push the hit count far beyond the weapon’s base numbers. Both are worth prioritizing before anything cosmetic.

• Cage Helmet — its unique Key Armor effect triggers Shrapnel one extra time whenever Shrapnel activates, lifting a 4-stack final shot from five triggers to six.
• MP57 Div-Evo (secondary) — A weakspot hit adds +1 Shrapnel target part for several seconds, increasing the per-trigger hit limit from five to six. Shrapnel has a 30% activation chance, and defeating an enemy guarantees activation for 4s.

For melee, the Kukri gives +30% attack and +15% crit rate for 10s after a heavy-attack kill, plus HP recovery; the Rusted Blade gives a +30% weapon attack multiplier after a kill on a 30s cooldown.

Butterfly’s Emissary deviation setup

Butterfly’s Emissary – Starry Night is the engine of the passive kill. Its first skill, Mitsuko’s Guidance, grants +30% Weapon DMG for 18s, makes your attacks count as guaranteed weakspot hits, and applies 34% Weapon Vulnerability for 10s. The guaranteed-weakspot effect matters because weakspot hits always trigger Shrapnel.

The second skill, Butterfly Swarm, fires tracking butterflies at up to 3-5 enemies within 40m, dealing five instances of 120% Psi Intensity Weapon DMG and triggering on-hit effects. Those on-hit triggers are what the single chambered bullet reads as repeated last-bullet shots.

05:40Deviation: Butterfly's Emissary

Calibration and weapon accessories

Calibration is applied at craft time. For the zero-shot approach, use the Portable Sniper Calibration Blueprint because it avoids the 10% attack penalty baked into the Rapid Sniper option. Rapid Sniper (Bolt-pulling Speed +50%, Post-Fire Delay -50%, Reload Efficiency +15%, Attack -10%) is better reserved for active shooting where fire cadence matters. For calibration substats, favor Weapon DMG first, then Crit Rate.

01:54Calibration Blueprints & Weapon Stats

For attachments, run the Stealthy Suppressor, Baseline Sniper Scope, Compact Infrared Indicator and Tactical SR Mag. Load Sniper Rifle AP Ammo for +15% damage per shot, +15% Psi Intensity, and +20% damage to shielded units.

02:35Weapon Accessories & Ammunition

Three armor setups

All three keep the Cage Helmet and differ in how they balance survival against burst. Pick based on how aggressive you want to play.

03:30Armor Setup 1: Savior Set (Shield Hybrid)

The Dark Resonance one-shot setup leans hardest into the deviation. Three pieces grant a +30% weapon and status damage boost for consumed power, and firing the ultimate adds the big instantaneous spike paired with the low-HP bonus from Treacherous Tides.

04:54Armor Setup 3: Dark Resonance (One-Shot Setup)

Two skins are worth slotting on top. Starfall Cowhide gives +8% Weapon DMG at 120 or more Stamina and doubles it while airborne. Four Lunar Rabbit Fur pieces activate Soaring Leap for +20% Weakspot DMG while airborne.

Mods, food, and Cradle Overrides

The mod suffixes matter as much as the mods themselves. These are the configurations that feed the Shrapnel loop.

Stack food before a fight. Crumbly Bread gives +25% to all weapon damage, Canned Steak adds +20% Shrapnel DMG, Bone-in Deviated Sausage adds +15% against bosses, and Whimsical Drink adds +10% Weapon DMG. Stardust Mushroom Soup covers stamina for the airborne skin bonuses.

For Cradle Overrides, take Precision Weapon Mastery, Deadly Combo, and Invincible Strike to scale the Shrapnel output, then Deviant Energy Defense, Shield Protection, Resilience, and Tactical Combo for survival. Energy Surge recovers one Deviant Power every 8 seconds between 9 PM and 3 AM in-game, which helps keep the deviation available.

07:19Cradle Override Setup