In Borderlands 4, cosmetic customization is more than just flair — it’s a badge of dedication. One such sought-after cosmetic is the Yabai head for Vex. In this guide, I’ll walk you through exactly how to unlock Yabai, step by step, using language that is clear and easy to follow. By the end, you’ll know the path and what to focus on to get this cool head style.
The Yabai head is a special head cosmetic for the Vault Hunter Vex. It is not given as a reward for finishing a mission; instead, it is unlocked by completing a particular challenge tied to customization upgrades. It’s a cosmetic that shows you’ve achieved full mastery over part of the game’s system.
The Core Requirement: All SDU Upgrades
The single biggest requirement for unlocking the Yabai head is to purchase all SDU upgrades for Vex. “SDU” stands for Storage, Deck, and Upgrade (or “Storage Deck Upgrades”), and these affect how much inventory space and capacity you have across different weapon classes and slots.
To meet the challenge, you must:
- Unlock every SDU upgrade available in the game
- Max out all storage “decks” for each weapon type
- Maximize the bank slot, backpack slots, and lost loot slots
In other words, you must fully upgrade every storage component tied to Vex’s customization and inventory before the Yabai challenge is considered completed.
How Many SDU Tokens Do You Need?
To fully purchase every SDU upgrade, you will need 3,225 SDU Tokens. These tokens are the currency in the SDU system. Because each successive upgrade costs more, you’ll need to gather a lot of them.
Here are the areas you have to upgrade:
- Pistol storage
- Assault Rifle storage
- SMG storage
- Shotgun storage
- Sniper Rifle storage
- Backpack
- Bank slot
- Lost loot slot
When every single one of those is maxed out, the challenge will be fulfilled, and Yabai unlocks.
How to Earn SDU Tokens Quickly
Gathering over three thousand tokens won’t happen overnight. You’ll need to complete many objectives, challenges, and collectible hunts. Focus on high-reward tasks. Below are the best sources of tokens:
High-yield sources:
- Clearing Safehouses
- Capturing or reclaiming Silos
- Clearing Drill Sites
- Completing Bunkers / Mines
- Tackling Order Bunkers
- Scavenging from Ancient Crawlers
- Activating Propaganda Speakers (survive waves of enemies)
- Solving Evocarium puzzles
- Using Loot Capsules in Capsule Machines
- Opening Electi Safes
- Exploring and opening Survivalist Caches
- Interacting with Auger Shrines (meditation spots)
- Sometimes encountering Vault Symbols (less rewarding, but still counts)
Your best bet is to roam the map, prioritize strong objectives you haven’t cleared yet, and stack multiple token sources in a single run. Don’t waste time chasing low yield Vault Symbols; focus effort on silos, bunkers, and larger objectives.
Step-by-Step Summary to Unlock Yabai
Here’s a simplified checklist you can follow:
- Access the SDU menu — know where you spend your SDU tokens.
- Plan upgrades — figure out how many tokens are needed per slot and weapon class.
- Farm tokens — tackle safehouses, silos, bunkers, etc., until you accumulate over 3,225 SDU tokens.
- Purchase upgrades methodically — upgrade one slot at a time; don’t leave any behind.
- Check challenge status — often the game tracks progress; once all are upgraded, the Yabai head unlocks.
Why Yabai Unlocked This Way
Borderlands 4 differentiates head cosmetics not merely by missions or kills, but by demonstrating mastery in systems. Yabai sits in a category where your success in game systems unlocks the aesthetic. It’s a way for players to show that they didn’t just play — they fully optimized.
Many other head cosmetics are unlocked by mission completions, kill counts, or unlocked via DLC or pack content. But Yabai is special: it’s tied directly to completing what many consider the SDU “completionist” challenge for Vex. Because of that, it has a kind of prestige.
Tips to Make It Easier
- Don’t upgrade everything haphazardly. Focus first on high cost or high utility decks, so each upgrade gives you more bang for the tokens spent.
- Revisit areas you skipped earlier. If you left behind silos or bunkers, come back with higher power to clear them.
- Team up with friends or co-op players. Some objectives are easier when tackled together.
- Track your SDU token balance and upgrade cost. Sometimes the final few upgrades require many tokens, so save accordingly.
