Mortal Shell 2 Best Proxima Build — Biosampler Loop
Updated August 24, 2026 · Checked for the current launch build
Official promotional screenshot: Steam / Cold Symmetry / Playstack
Proxima build at a glance
Choose the right Proxima branch
| Variant | When it fits | Core package | Tradeoff |
|---|---|---|---|
| Protected Biosampler | First run | Axe & Dagger, Duality; Attunement → Exoshell → Biohazard | Simple and cheap, but not yet a complete Lightning package |
| Lightning / Stasis | NG+ | Axatana, Duality, Voltaic Crown, Acolyte; add Seizure and Discharge | Strong groups and control; boss play cannot rely on chain spread |
The branches share the same core Shell. Build the first functional loop before copying the late package; several NG+ components arrive too late to solve an early-game problem.
Core and optional Tarstones
Core package
- Duality Stone — extra light hits accelerate Resolve and status buildup
- Arbiter's Prize — Bloodcurse pressure benefits from the fast hit count
- Auspicious Stone — reliable critical chance for the melee half of the loop
Optional slots
- Headman's Stone after critical chance is established
- A Lightning-oriented infusion for an NG+ variant
- Bulwark Stone for safer pack clearing after Balance Patch 1's buff
Proxima skill priority
| Order | Skill | Why now |
|---|---|---|
| 1 | Attunement | First priority because Biosampler cannot be the center of the build if its Resolve cost prevents repeat casts. |
| 2 | Exoshell | Protects Proxima during the ability animation and removes the most dangerous part of using Biosampler at close range. |
| 3 | Biohazard | Adds the damage and Lightning pressure once cost and safety are solved. |
| 4 | Seizure | Adds Stasis and crowd-control value; buy it after the basic one-target loop is stable. |
See the full Shell skill-tree priority guide for the currency rules and early-versus-late investment checkpoints.
How to assemble the build
- Unlock Proxima at the shattered beacon north of Widow's Overlook.
- Prioritize Attunement and Exoshell before damage nodes so Biosampler is affordable and safe.
- Pair Axe & Dagger with Duality Stone; add Arbiter's Prize only after you can keep a full light chain on target.
- Use the Triarch Repeater as a pressure tool, not as a replacement for the Resolve-generating melee loop.
Combat loop
- Hook a small enemy into isolation, or let Biosampler pull Proxima to a large target after its attack ends.
- Use the protected Biosampler hit to start Lightning/Stasis pressure.
- Land a standing Axe & Dagger chain while the target is controlled, rebuilding Resolve through repeated hits.
- Harden through the first retaliation, disengage, then cast Biosampler again when the enemy commits.
Where the build works — and where it fails
Strengths
- High early survivability
- Excellent control against groups
- Clear progression from starter setup to NG+ Lightning build
Weaknesses
- Resolve-starved before Attunement
- Biosampler can pull you into danger
- Several recommended stones arrive after the Shell itself
Cheaper alternatives
- Axatana is a valid substitute if it is already upgraded.
- Stay on Untarnished Seal if you are building around parry and riposte instead of Harden windows.
Common mistakes
- Copying an endgame loadout before obtaining the skill that makes its ability affordable or safe.
- Replacing an upgraded weapon with a nominally higher-tier weapon at level zero.
- Equipping critical-damage bonuses before building enough critical chance to trigger them consistently.
- Spending the Resolve needed for the Shell ability on a sidearm shot with no immediate purpose.
- Testing only on normal enemies; kill-triggered effects can disappear in an add-free boss arena.
Official gameplay reveal — Proxima's Biosampler in action
Official gameplay demonstrates animation timing and spacing. The loadout is an independent recommendation synthesized from the sources on this page.
Related guides
All builds · Proxima unlock and abilities · Skill priority · Duality Stone · Upgrade materials
Frequently asked questions
What is the best weapon for a Proxima build?
Axe & Dagger is the primary recommendation for this build. If the alternative in the guide is already upgraded, keep the developed weapon until the new one has its key Tarstone and upgrade levels.
Which Proxima skill should I upgrade first?
Attunement. It fixes the cost, safety, or output of the Shell's core ability before you spend points on secondary effects.
Is this Proxima build good for bosses?
High early survivability. Read the weakness section before committing because boss rooms can remove kill-triggered sustain and shorten safe attack windows.
Will this build survive later balance patches?
The exact damage ranking may change. The page focuses on a repeatable combat loop and labels optional components so you can replace a nerfed Tarstone without rebuilding the entire Shell.