The Staff of Ice in *Call of Duty: Black Ops 6* Zombies is a unique Wonder Weapon; its base form is underwhelming, but its upgraded version, Ull's Arrow, becomes indispensable for high-round survival and Easter egg hunts. This guide details the upgrade process.
Prerequisites for Upgrading the Staff of Ice
Before upgrading, you need two things: the Staff of Ice itself (obtained from the Mystery Box or by assembling its three parts) and access to the Dark Aether Nexus (achieved by opening the Door to Nowhere).
How to Upgrade the Staff of Ice
Step 1: Freezing Dark Aether Crystals

Freeze three Dark Aether Crystals rapidly using the Staff of Ice. These crystals are found in underground lanterns (black frame, purple glow). Perks like Stamin-Up and PHD Flopper (with Tribologist) significantly improve your speed. Strategically plan your route; the optimal path starts in the tomb area, then the Shrine of the Hierophants, and finally the lantern near the Subterranean Temple entrance (avoiding the lantern near Quick Revive due to distance). Successfully freezing the crystals triggers a quote from Archibald, signaling your next step in the Dark Aether Nexus.
Step 2: Floating Rocks in the Dark Aether Nexus

Within the Dark Aether Nexus, locate three floating rocks with glowing purple Runes. Shoot each Rune with the Staff of Ice (a hitmarker confirms success). This will lower the rocks, making the Runes easier to target. A sniper rifle or weapon with zoom can aid accuracy. The order doesn't matter; shoot all three.
Step 3: Rune Symbols Puzzle

After completing Step 2, find a stone wall replacing a portal back to the main map. On this wall are glowing Runes; three match the symbols from the floating rocks. Shoot these three matching Runes with the Staff of Ice. The portal will open regardless of your choices, but incorrect selections teleport you to a random location within the Dark Aether Nexus. Multiple failures may require waiting for the next round. Correct symbols lead to a floating rock with a purple orb. Interact with the orb.
Step 4: Soul Chest Orb Escort

After interacting with the orb, it begins moving. Kill zombies near it; their essence fuels the orb's progress. Keep killing to maintain its movement. The orb eventually settles in a central structure, forming a small purple portal. Interact with the portal to upgrade the Staff of Ice to Ull's Arrow.
Ull's Arrow: Upgraded Staff of Ice Abilities
Ull's Arrow boasts a powerful charged attack with high AoE damage and an alternate fire mode for reviving downed players, similar to its predecessors in Black Ops 2 and 3.
Call of Duty: Black Ops 6 is available now on PlayStation, Xbox, and PC.