Destiny 2: How to Unlock and Complete Oblation for Cull’s Shadow

The failure point on this one is brutally simple: players finish Scarlet Keep, grab the chest, leave the strike, and never realize the real unlock starts after the boss dies. Cull’s Shadow is locked behind a hidden quest chain, and almost every dead end comes from missing one of the steps below rather than hitting a bug.

The short version

• Equip a Weapon of Sorrow before you start, and keep it on the whole time.
• Run the Scarlet Keep strike. After the boss, shoot the hidden green Hive runes in the order shown by the beige symbols on the gate — top to bottom.
• Sweep exactly four Moon locations: Archer’s Line, Anchor of Light, Hellmouth, and Sorrow’s Harbor. Each one has a Hive crystal to interact with.
• Start Oblation: Bloodline from the tunnel that runs under the bridge into the Scarlet Keep in Sorrow’s Harbor.
• The reward is Cull’s Shadow, an Exotic Kinetic Fusion Rifle that itself counts as a Weapon of Sorrow.

Treat this as a hidden-steps quest, not a normal mission pickup. The game does not confirm much along the way, so the trick is doing every step deliberately instead of rushing the strike and assuming the node will appear on its own.

What to have ready before you start

• A Weapon of Sorrow equipped before you load into Scarlet Keep — this is the trigger condition, not optional.
• Access to the Moon and the Scarlet Keep strike.
• A loadout built for steady add clear and safe boss damage, not pure speed.

If you complete the strike without a Weapon of Sorrow equipped, the run will not count toward the unlock. Rerun it properly rather than troubleshooting every later step first.

Step 1: Trigger the hidden step in Scarlet Keep

Launch Scarlet Keep with your Weapon of Sorrow equipped and finish the strike normally. The important part comes after the boss encounter. Do not orbit out as soon as the fight ends — stay in the final area for the hidden symbol step.

How the symbol step works

With your Weapon of Sorrow equipped, beige symbols appear on the gate. Those symbols tell you which hidden green Hive runes to shoot. Shoot them in the order shown — top to bottom — to register the next stage. This is a match-the-clue puzzle, not random Hive markings, so read the gate first and then find the matching runes instead of firing at every glyph you see.

If your progress does not move after this, the cause is almost always one of three things: no Weapon of Sorrow equipped, leaving the area too early, or shooting the runes out of order. Slow down and redo the sequence cleanly.

• Do not swap off the Weapon of Sorrow before the strike is complete.
• Do not leave the area immediately after the boss dies.
• Shoot the runes in the order the gate symbols show — top to bottom — not in any order.

Step 2: Sweep four Moon locations for Hive crystals

After Scarlet Keep, the unlock moves to the Moon. You do not need to comb every patrol zone — only four locations matter, and each one has a Hive crystal to interact with:

• Archer’s Line
• Anchor of Light
• Hellmouth
• Sorrow’s Harbor

Drop into each zone and find its Hive crystal to interact with. Ending the loop at Sorrow’s Harbor is convenient because that is where you start the mission next — no extra backtracking once all four crystals are done.

If your progress stalls here, it is almost always one crystal you skipped. Recheck the four zones above before assuming anything earlier went wrong.

Step 3: Start Oblation: Bloodline in Sorrow’s Harbor

With all four Hive crystals done, head to Sorrow’s Harbor. Start Oblation: Bloodline from the tunnel that runs under the bridge into the Scarlet Keep, accessed below the east side of the bridge.

If the mission is not available there, the most likely cause is a missed Moon crystal rather than a bug. A quick recheck of the four zones is faster than replaying the strike. The strike step is front-loaded; the Moon crystals are where most unlock attempts quietly break. For a full walkthrough of the mission itself once it opens, see our guide to Oblation: Bloodline for Cull’s Shadow.

Best loadout approach for Oblation: Bloodline

For the mission itself, build for control. Exotic missions punish deaths far more than they reward raw DPS, so you want a setup that survives Hive pressure, kills majors quickly, and still saves real boss damage for the safe windows.

• A primary weapon you trust for nonstop add clear.
• A special weapon or ability package that deletes dangerous majors quickly.
• A heavy weapon saved mainly for boss phases or panic clears.
• A subclass with a dependable survival tool — healing, damage resistance, invisibility, suspend, or freeze.
• Ammo and survivability mods over pure glass-cannon damage, especially solo.

Exotic missions are rarely lost because your damage number is too low. They are lost because you burn heavy too early, get swarmed during a mechanic, or die forcing a damage phase that was never safe.

How to play Bloodline without wiping

The most dependable approach is a control-first rhythm: clear the room, stabilize your position, then do the objective. Do not interact first and hope you survive the spawn response afterward.

In traversal and mechanic rooms

When the mission shows an interactable object or progression trigger, make space before touching it. Kill the nearest major, clear the trash that can body-block you, reload everything, then advance the mechanic. Solo, stay off the center of the room: move along the outer edge, keep hard cover between you and the densest lane of fire, and rotate once adds stack up.

In the boss encounter

Treat boss damage as the last part of each cycle, not the first. The common wipe is greed: the boss becomes hittable, you dump everything, then fresh adds or a mechanic check collapses the run. Remove the most dangerous threats, confirm your retreat path, then start damage. Save ammo and supers for the transitions where the room is most likely to spiral.

Solo and fireteam adjustments

Solo players should lean into survival and accept a slower clear — a clean six-minute boss phase beats a reset. In a fireteam, split roles: one on add control, one on objective awareness, one on burst damage. If a room uses symbols or crystal cues, call them out immediately instead of assuming everyone saw the same thing.

Common mistakes

• No Weapon of Sorrow equipped: the Scarlet Keep run will not count. Re-equip it and rerun the strike.
• Shooting the runes in the wrong order: match the gate symbols top to bottom, not in any order you like.
• Trying to sweep the whole Moon: only four zones matter — Archer’s Line, Anchor of Light, Hellmouth, Sorrow’s Harbor. Doing more is wasted time.
• Looking for the mission node in the open: it starts from the under-bridge tunnel into the Scarlet Keep, not out on the surface.
• Building for DPS over survival: rebuild for control and stop saving all heavy for a “perfect” phase that may never come.

Practical takeaway

Equip a Weapon of Sorrow, finish Scarlet Keep, then shoot the hidden green runes in the order the gate symbols show. Sweep the four Moon Hive crystals — Archer’s Line, Anchor of Light, Hellmouth, Sorrow’s Harbor — and start Oblation: Bloodline from the tunnel under the bridge into the Scarlet Keep. Go in with a survival-first loadout, play each room like control matters more than speed, and you walk out with Cull’s Shadow, the Exotic Kinetic Fusion Rifle. While you are chasing exotics, our guide to every Monument of Triumph Catalyst and our breakdown of upgrading those Catalysts fast are worth a look.