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, the Ull's Arrow, is crucial for high-round survival and Easter egg hunts. Here's how to upgrade it.
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 crafting it from three parts) and access to the Dark Aether Nexus. Open the Door to Nowhere early to gain access.
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 fire). Perks like Stamin-Up and PHD Flopper (with Tribologist) significantly aid this step. Optimize your route; a suggested path is Tomb area, Shrine of the Hierophants, then Subterranean Temple entrance lantern (avoiding the lantern near Quick Revive due to distance). Successful completion triggers a quote from Archibald. Then, enter the Dark Aether Nexus.
Step 2: Dark Aether Nexus Floating Rocks

Locate three floating rocks with glowing purple Runes in the Dark Aether Nexus. Shoot each Rune with the Staff of Ice (a hitmarker confirms success). This lowers the rocks, making Rune identification easier. A scoped weapon might improve accuracy. The order doesn't matter; shoot all three.
Step 3: Rune Symbols Puzzle

After Step 2, a portal back to the main map will be replaced by a wall with Runic icons. Three match the symbols from the floating rocks. Shoot these three with the Staff of Ice. The portal will open/re-open regardless of accuracy; incorrect symbols will teleport you to an awkward location in the Dark Aether Nexus. If unsuccessful, wait a round. Correct symbols place you on a floating rock with a purple orb. Interact with it.
Step 4: Soul Chest Orb Escort

The Orb will move; follow it and kill zombies near it. Their essence fuels the Orb. Keep killing to maintain momentum. The Orb will eventually settle in a central structure, creating a small purple portal. Interact with it to upgrade the Staff of Ice to the Ull's Arrow.
Ull's Arrow: Upgraded Staff of Ice Abilities
The Ull's Arrow boasts a powerful charged AoE attack and an alternate fire mode for reviving downed players, similar to its Black Ops 2 and 3 counterparts.
Call of Duty: Black Ops 6 is available now on PlayStation, Xbox, and PC.