The Staff of Ice in *Call of Duty: Black Ops 6* Zombies is a unique Wonder Weapon. While its base form is relatively weak, 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 (obtainable 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, glowing purple fire). Perks like Stamin-Up and PHD Flopper (with Tribologist) significantly improve your speed, crucial for this step. Optimize your route; starting in the tomb area, then the Shrine of the Hierophants, and finally the Subterranean Temple entrance lantern is usually the fastest, provided a suitable lantern is active near the tomb. 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

Three floating rocks with glowing purple runes appear in the Dark Aether Nexus. Each rune has a unique symbol. Note these symbols. Shoot each rune with the Staff of Ice; a hitmarker confirms a successful shot. This will cause the rock to descend, making the rune easier to target. A sniper rifle or weapon with zoom can aid in this process. The order doesn't matter; shoot all three.
Step 3: Rune Symbols Puzzle

Find a stone wall replacing a portal back to the main map. On this wall, three runes match those you noted earlier. Shoot these matching runes with the Staff of Ice. The portal will open (regardless of correctness), but only shooting the correct runes will teleport you to the correct location. Incorrect choices result in a mid-air drop back into the Dark Aether Nexus; you may need to wait for the next round to retry. Correctly shooting the runes places you on a floating rock with a purple orb. Interact with it.
Step 4: Soul Chest Orb Escort

Follow the moving orb, killing zombies near it. Killed zombies contribute purple energy to the orb, fueling its movement. Guide it to the central structure in the Dark Aether Nexus, where it creates a small purple portal. Interact with the portal to upgrade your Staff of Ice to Ull's Arrow.
Ull's Arrow: Upgraded Staff of Ice
Ull's Arrow boasts a powerful charged attack with high AoE damage, similar to its Black Ops 2 and 3 counterparts. It also gains an alternate fire mode capable of reviving downed teammates.
Call of Duty: Black Ops 6 is available now on PlayStation, Xbox, and PC.