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The correct agent leveling order in Zenless Zone Zero isn’t decided by which agent hits the highest number — it’s decided by what the endgame actually demands. Shiyu Defense requires two non-overlapping teams of three agents each, which means a functional second squad matters more than pushing your favorite agent to the absolute ceiling. This guide walks through what to invest in first, when to switch focus to W-Engines, when Drive Discs actually become worth the time, and why the real limiting factor isn’t materials at all — it’s how much energy the game lets you spend per day. Written for version 3.1 (released July 29, 2026); if you’re reading an older guide, the general order below still holds, but some material names and unlock thresholds have moved.
Agent leveling in Zenless Zone Zero actually covers four separate systems that all draw from the same pool of time and materials. Understanding what each one does — and which one to touch first — is the whole game here.
Each of these systems is gated separately, and each has its own place in the priority order. Skipping straight to Drive Discs because a build guide says so, before your Agent Level and Core Skill are even settled, is one of the fastest ways to waste a week of Battery.
TL;DR
- Leveling order is set by Shiyu Defense’s dual-team requirement, not by how strong one agent can get — a second team beats a maxed first team.
- Priority sequence: Agent Level and Core Skill on your main three first, then W-Engine once level plateaus, then Drive Discs last, once the roster is settled.
- The bottleneck is Battery Charge and its 24-hour regen cycle, not raw material scarcity — this is a calendar problem, not a farming problem.
- The classic mistake is maxing one agent’s level, W-Engine and discs before a second team exists, then hitting a Shiyu Defense wall where that agent sits unused.
- Passive systems like Tactics Courses let you level bench agents without spending Battery at all.
| System | What it raises | What it costs |
|---|---|---|
| Agent Level | Base ATK, DEF, HP; unlocks higher promotion tiers | Investigator Logs (EXP) and Denny |
| Core Skill | Passive power spike at set level thresholds | Certification Seals and Denny |
| W-Engine | Flat stats plus a weapon passive effect | W-Engine EXP, Components, and duplicate copies for refinement |
| Drive Discs | Substats and 2-piece/4-piece set bonuses | Farmed discs plus tuning materials from dismantled copies |
Where to Get Leveling Materials in Zenless Zone Zero
Most of your early materials come from just playing the story and running the Investigator Training Course inside the HIA Club building in Lumina Square, which hands out Denny, Prototype Seals, and W-Engine Specialization materials for completing lesson exercises. Once an agent is benched, you can also assign them to a Tactics Course to gain passive EXP per real-time minute without touching combat — a run finishes in real-time hours and stops automatically once the agent hits its promotion cap. Later on, Combat Simulation becomes your source for W-Engine Components, and Routine Cleanup at higher Inter-Knot levels becomes the main source of Drive Discs. Weekly Notorious Hunt targets round things out with character-specific ascension and skill materials that don’t cost Battery at all.
| Source | What you get | Requirement | Who it suits |
|---|---|---|---|
| Investigator Training Course | Prototype Seals, Denny, W-Engine materials, EXP | None major, available early | Every player, especially new accounts |
| Tactics Courses (passive) | EXP for a benched agent, capped at promotion level or Lv. 60 | Agent must be below current promotion cap | Time-limited players, off-team agents |
| Combat Simulation | W-Engine Specialization materials and Components | Battery Charge | Mid-game W-Engine pushes |
| Routine Cleanup | Drive Discs, S-Rank drops from higher-level stages | Battery Charge, scales with Inter-Knot level | Endgame disc farming |
| Notorious Hunt (weekly) | Character-specific ascension and skill materials | Weekly reset, no Battery cost | Everyone, free every week |
Best Order to Farm and Invest: What to Level First in ZZZ
This is the table that actually answers the question. Read it top to bottom in order — each row assumes the one above it is roughly settled, not necessarily maxed.
Warning
Drive Disc farming is the most Battery-expensive activity in the game per meaningful upgrade. Starting it before your team comps are locked means you’ll re-farm the same partitions for a different agent later, burning weeks you can’t get back.
For deeper context on why the endgame is structured this way, the Shiyu Defense, Deadly Assault, and Hollow Zero breakdown covers exactly what each mode expects from a roster before you start pouring materials into it.
| Invest in | What it gives | When to start | Limited by |
|---|---|---|---|
| Agent Level on your main three | Base stat scaling, unlocks promotion tiers | Immediately, every version | Investigator Logs and Denny, gated by Inter-Knot level |
| Core Skill on those same agents | A passive power jump at set level thresholds | As soon as the agent reaches the threshold | Certification Seals |
| Basic W-Engine (S-Rank or a solid A-Rank) | Flat stats plus a usable passive | Once Agent Level plateaus at a promotion cap | W-Engine EXP and Components, Battery-gated |
| Skills matching the agent's rotation | Actual combat effectiveness, not just stat sheet numbers | After core stats and W-Engine are set | Element-specific skill materials, Denny |
| Your second team's core three | Roster width — required to clear both halves of Shiyu Defense | As soon as team one can clear current content, don't wait for "done" | The same Battery pool as team one, directly competing for it |
| Targeted Drive Disc tuning | Substats and set bonuses, the largest single power spike available | Once your roster and comps are settled, not before | Battery Charge and dismantled-disc tuning materials, the heaviest time sink in the game |
Fastest Way to Level Agents: Comparing the Farming Methods
| Method | Speed | Effort | Best for |
|---|---|---|---|
| Tactics Course (passive) | Slow but free | Low, set and forget | Leveling bench agents without spending Battery |
| Investigator Logs from story/commissions | Medium, front-loaded | Low | Early Agent Level before Battery matters much |
| Combat Simulation | Medium | Medium | W-Engine EXP and Components |
| Routine Cleanup | Slow, hard Battery-capped | High, requires targeted runs | Drive Disc farming once your roster is fixed |
| Notorious Hunt (weekly) | Fixed, once per week | Low | Free character-specific ascension materials |
Step-by-Step: A Weekly Agent Leveling Routine
Follow this sequence to get it done fast.
-
1
Clear weekly free content first
spend the free Notorious Hunt attempts and clear Shiyu Defense and Hollow Zero progression before touching Battery, since none of these cost it.
-
2
Spend Battery Charge daily, don't let it cap
Battery caps at 240 and regenerates on a fixed cycle, so sitting at the cap for hours wastes regeneration you'll never get back.
-
3
Feed the agent you actually play
put Investigator Logs and skill materials into the agent whose rotation you're running, not the one with the highest rarity sitting on the bench.
-
4
Assign benched agents to a Tactics Course
this levels a second-team member passively while your Battery goes toward the agent currently in rotation.
-
5
Check your promotion cap before farming ahead
pushing an agent's level or W-Engine past what your Inter-Knot level allows just parks materials in a stat you can't use yet.
-
6
Only start Drive Disc tuning once your two teams are fixed
lock the comps first, then commit Battery to Routine Cleanup for the specific partitions those comps need.
Sources of Materials, and Why the Real Limit Is Energy
New players consistently misread the bottleneck in this game. It looks like a materials problem — not enough Certification Seals, not enough Components — but it’s actually a time problem. Battery Charge caps at a fixed amount and regenerates on a fixed schedule, so no amount of grinding compresses that into a shorter week. You can buy your way past the cap with currency, but the underlying regeneration rate doesn’t change, which is exactly why the leveling order matters so much: every point of Battery spent on an agent who won’t be in either of your two teams is a point that didn’t go toward getting a real second squad off the ground.
Why Drive Disc Tuning Exists
Dismantling farmed discs into tuning materials and spending them at Sixth Street’s disc-tuning facility lets you guarantee a main stat instead of gambling on a fresh drop every time. It’s still Battery-expensive, but it converts pure RNG into a controllable, if slow, upgrade path — which matters a lot once you’re only farming for one or two specific partitions instead of a whole fresh kit.
Why Tactics Courses Matter More Than Players Realize
A Tactics Course runs on real-time hours, not Battery, and doesn’t lock the agent out of anything — they can still run commissions, Shiyu Defense, or Hollow Zero while studying. For a second team you’re not actively piloting yet, this is close to free Agent Level that would otherwise compete with your main team for the same Investigator Logs.
Common Misconceptions About Agent Leveling in ZZZ
Myth: A Maxed W-Engine Beats a Half-Built Disc Set
Not automatically. A high-level W-Engine sitting on an agent whose Agent Level and Core Skill are still low is stat inflation on a foundation that isn’t there yet. Level and Core Skill first, then let the W-Engine catch up.
Myth: You Need Six Agents Fully Leveled to Clear Shiyu Defense
You need six agents who are functional, not six who are maxed. Shiyu Defense’s two-team structure rewards a second team that clears its side reliably far more than a first team that overkills its own.
Myth: Drive Disc Farming Is Always the Best Use of Battery
Only once your comps are locked. Farming discs for an agent who might get benched next patch, or for a slot your final comp doesn’t even use, is the single most common way to burn weeks of Battery for nothing.
Our Take: Is This Leveling Order Worth Following?
Our Take
Yes — because the alternative is a maxed favorite that can’t clear half of Shiyu Defense on its own.
The order in this guide isn’t a power-maximizing trick, it’s a description of what the endgame actually checks for. Players who ignore it tend to end up with one overinvested agent and a bench of half-leveled backups, which is precisely the wall the brief describes: a maxed agent that’s useless in a second team because that team doesn’t exist yet. Follow the order, respect the Battery cap as a calendar constraint rather than a farming problem, and the roster comes together roughly the same speed either way — just without the dead-end detour.