Tenebris Somnia Achievement Guide: How to Unlock All Four Endings

All Four Tenebris Somnia Endings at a Glance

Tenebris Somnia has four ending achievements, and two of them can be unlocked from the same late-game save. The other two are hidden routes that require prerequisites, a new playthrough, and very specific steps. That split is why a focused Tenebris Somnia achievement guide is more useful than a general walkthrough: you need to know what to save, what to skip, and which actions lock you into a different finale.

This article contains ending spoilers. The route details below come from NoobFeed's all-endings walkthrough, published October 18, 2026, so treat them as community reports rather than official documentation. For official store and platform details, check the Tenebris Somnia Steam page.

A good Tenebris Somnia achievement guide should make the main save point obvious. Make a manual save immediately after you obtain the Aurifer and before you kill any Relicta. From there, you can finish the no-kill ending, reload, and take the opposite route without replaying the earlier puzzles.

SOLVE ET COAGULA: The No-Kill Ending

For this section of the Tenebris Somnia achievement guide, treat the Aurifer as a story item, not a weapon. This route is commonly considered the good ending, and its requirement is strict: no Relicta can die by your Aurifer after you obtain it.

1. Play the main story until the Aurifer knife is forged and added to your inventory.
2. Create a manual save before you continue into the final section.
3. Move toward the Séptimo Arte theater and watch for Relicta ghosts.
4. Run past the Relicta instead of attacking them. Do not use the Aurifer to kill even one.
5. Continue through the finale, defeat Lacuna, and finish the game to unlock SOLVE ET COAGULA.

A single kill changes the result. If you think you may have killed a Relicta by mistake, reload a save from before that encounter. Once the achievement appears, you can reload your earlier save and pursue Ending 2.

MAGNUM OPUS: The Aurifer Kill Route

The second half of this Tenebris Somnia achievement guide flips the rule. MAGNUM OPUS is commonly considered the bad ending, and it triggers when you kill at least one Relicta ghost with the Aurifer. You do not need to kill every Relicta; one confirmed kill is enough to change the finale.

1. Load your manual save from after you obtain the Aurifer, or continue a run where you have not completed the final section.
2. Return to the area where Relicta ghosts appear.
3. Attack a Relicta with the Aurifer and make sure it actually dies. A hit alone is not enough.
4. Continue through the final area toward the Séptimo Arte theater.
5. Complete the alternate finale and defeat Hermes to unlock MAGNUM OPUS.

Once a Relicta kill is registered, you cannot return to the no-kill ending in the same run unless you reload a save from before the kill. That is why the shared save matters.

The Shared Save Trick

Create a manual save immediately after obtaining the Aurifer and before any Relicta kill. Complete the game without killing a Relicta to unlock SOLVE ET COAGULA. Then reload that save, kill one Relicta with the Aurifer, and finish the alternate finale to unlock MAGNUM OPUS. You still need to complete each finale separately, but you avoid replaying the earlier story and puzzles.

VIVUS EX MORTIBUS: Bible and Iron Cross Checklist

VIVUS EX MORTIBUS is the longest branch in this Tenebris Somnia achievement guide. It requires you to complete Endings 1 and 2 first, then start a new game. On that new run, collect the Bible from the ground-floor lobby's glass table and use it to trigger three hidden encounters. Each encounter rewards an Iron Cross. You must complete these encounters before solving the related puzzles normally.

1. Collect the Bible. After starting the new game, search the ground-floor lobby and pick up the Bible from the glass table. Keep it in your inventory as you progress.

2. Get the first Iron Cross. Go to the second-floor apartment living room and trigger the hidden encounter before completing the normal TV puzzle. Use the Bible in the living room, find the circle of planetary symbols on the floor, stand on the Man/Mars symbol, and run counterclockwise around the circle six times. Defeat the enemies that appear and collect the first Iron Cross. If you solve the TV puzzle first, the Bible may be removed from your inventory, so do this ritual early.

3. Get the second Iron Cross. Go to the Community Center on the first floor and find the locked projector room. Use the Bible on the lock to trigger the hidden encounter, then enter code 6666 when prompted. Defeat the enemies and pick up the second Iron Cross. Do not open the projector room normally before triggering this encounter.

4. Get the third Iron Cross. Go to Floor 0 and find the green door leading to the cinematography room, before entering the Copper Key-locked door. Enter the room and use the Bible to trigger the hidden encounter. Find the camera on the tripod, connect the yellow RCA cable, and switch between the camera channels until enemies appear. Defeat them and collect the third Iron Cross.

5. Open the secret route. Return to the third floor and find the blue door to the left of the elevator. Look for the marked wall or poster and insert all three Iron Crosses. Enter the secret doorway, continue through the route, and defeat Amy to unlock VIVUS EX MORTIBUS. If the doorway does not open, confirm that all three crosses were collected in the same playthrough.

RENUNTIATIO and the Fastest Unlock Order

Ending 4 is a short but prerequisite-heavy step in the Tenebris Somnia achievement guide. You must complete Endings 1 and 2 first, then start a new game. After the opening sequence, stay in the ground-floor lobby and find the building's glass entrance door on the left side of the room. Open your inventory, select the Apartment Key, and use it on the front entrance instead of taking the elevator to Ivan's apartment. Julia will leave the building and trigger RENUNTIATIO.

This route skips the Bible, the apartment puzzles, and the final bosses. Once the ending sequence plays, the achievement unlocks.

For a clean Tenebris Somnia achievement guide run, use this order:

1. Save after obtaining the Aurifer, then complete the no-kill route for SOLVE ET COAGULA.
2. Reload that save, kill one Relicta with the Aurifer, and finish the alternate finale for MAGNUM OPUS.
3. Start a new game and use the Apartment Key on the lobby entrance for RENUNTIATIO.
4. Start another new game, collect the Bible and all three Iron Crosses, then defeat Amy for VIVUS EX MORTIBUS.

This order follows the source walkthrough's fastest route: the two main endings come from one save, Ending 4 is handled with a quick new game, and Ending 3 is saved for last because it requires the most setup.

FAQ: Tenebris Somnia Achievement Guide

Which ending is considered good or bad in Tenebris Somnia?

Community reports call SOLVE ET COAGULA the good ending and MAGNUM OPUS the bad ending. The difference comes down to whether you spare every Relicta after obtaining the Aurifer or kill at least one with it.

Can I unlock both main endings from one save?

Yes. Make a manual save immediately after you obtain the Aurifer and before any Relicta kill. Finish the no-kill route first, reload that save, kill one Relicta, and complete the alternate finale.

Do all three Iron Crosses need to be collected in one playthrough?

Yes. If the secret doorway on the third floor does not open, verify that all three Iron Crosses came from the same playthrough and that you completed each Bible encounter before solving its related puzzle normally.

What is the fastest order for a Tenebris Somnia achievement guide run?

Unlock both main endings from the same post-Aurifer save, then start a new game for RENUNTIATIO, then start another new game for VIVUS EX MORTIBUS. That order follows the source walkthrough's fastest route and avoids unnecessary replays.