ZZZ Shiyu Defense — Unlock, Reset & How It Differs From Deadly Assault | Zenless Zone Zero

You need to reach Inter-Knot Level 35, get promoted to "Certified Proxy," then finish the mode's intro commission. That commission is tied to the main story, so simply pushing the campaign gets you there. Once unlocked, you enter Shiyu Defense from the endgame combat menu.

Note: the old requirement (Level 20) was changed in patch 2.5, so it is now Level 35.

Shiyu Defense splits into three areas:

• Stable Node and Disputed Node: unlocked as you progress and never reset. These are one-time first-clear rewards worth a few thousand Polychrome in total — roughly 3,000 and 1,600. Note that Disputed Node's early stages can be cleared with a single team; only from stage 3 onward are two teams required.
• Critical Node: resets on a schedule and is your steady, repeatable Polychrome source. This is the part players farm each cycle.

New players should clear Stable and Disputed first for the one-time Polychrome, then tackle Critical Node.

The Critical Node has several stages, and each one asks for two teams — that's 6 agents and 2 Bangboo. Your job is to wipe out every enemy inside a time limit; the faster you clear, the higher your grade. Each stage has its own target time and three reward tiers: B for clearing, A for beating the target time, and S for clearing comfortably under it — aim for S on every stage to collect the full Polychrome. Because you field two teams, you need a wide roster, not all your gear on one squad.

Prep tip: push your Inter-Knot Level toward 50 so your agents can reach their Lv60 cap — both modes get much easier.

Reset: the Critical Node swaps its enemy layout and buffs every two weeks (on a Friday, at 04:00 server time). Each reset is a fresh Polychrome farm — up to roughly 780 Polychrome per cycle (varies by patch). Stable and Disputed do not change.

Deadly Assault is the second endgame mode. It unlocks at Inter-Knot Level 40, once Shiyu Defense is open, after you finish the "Deadly Situation" commission (talk at Scott's Outpost).

You fight three bosses, 3 minutes each, and the bosses have effectively endless HP — you don't need to kill them, you rack up points. Your score blends raw damage with clean defensive play — Perfect Assists, Chain Attacks, and the like. Rewards stack per star: each of the first six stars gives 50 Polychrome, so 6 stars caps the Polychrome at 300. But the full 720 Investigation Merits and 225,000 Denny only come at all 9 stars (3 bosses × 3 stars) — from the 7th star on there's no more Polychrome, just Merits and Denny. It resets every two weeks, swapping both bosses and buffs.

Both are endgame modes, both reset every two weeks, and both pay Polychrome — but they play very differently:

In short: Shiyu Defense tests your clear speed, while Deadly Assault tests your roster depth (three non-overlapping teams). The two modes update on alternating weeks.

New players should start with Shiyu Defense: it unlocks earlier (Level 35), lets you reuse agents so two decent teams are enough, and its Stable/Disputed Nodes hand out chunky one-time rewards. Once you have three solid non-overlapping teams, move on to Deadly Assault (Level 40) for another 300 Polychrome per cycle. Both are your top repeatable Polychrome sources for gacha — don't miss a reset.

Every time the Critical Node rotates, the game swaps both the enemy lineup and that rotation's buff. The buff is not decoration — it usually multiplies one specific playstyle (rewarding Anomaly application, say, or rewarding Stun breaks). So before you build a team, do two things in this order:

1. Read this rotation's buff first, pick Agents second. If the buff rewards Anomaly, a moderately-built Anomaly team will out-perform a beautifully-built raw-damage team, because the buff multiplies what you're actually doing.
2. Check the stage's enemy weaknesses. Hitting the right element builds the Daze bar far faster, and S-rank is graded on time — breaking Stun early is the single strongest way to cut the clock.

If you're shaky on how the Daze bar works, read the Stun/Daze mechanics first; and to look up which boss is weak to what, the table in the weekly boss farming route lists every boss's weakness and resistance.

S-rank is graded on clear time, so every second you spend not dealing damage is a second lost. The four biggest time sinks:

• Don't basic-attack for too long. ZZZ's real damage lives in the post-Stun window — dump your skills, Ultimate and Chain Attacks while the enemy is Stunned instead of spraying them while it's still standing.
• Use Quick Assist instead of just dodging. A perfect dodge/parry opens a free counter-swap — you avoid the hit AND keep building Daze without losing tempo. See Chain Attacks & Quick Assist.
• Spread investment across both teams. The Critical Node forces two teams; plenty of players stack everything on team 1 and then drop a rank on team 2's stage. Your total is dragged down by the weaker squad, so bring team 2 up to "good enough" before polishing team 1.
• Match elements to the enemies. If a stage mixes two enemy types, build each team to answer one of them rather than fielding one generalist team that's mediocre into both.

If you're unsure which team core fits, cross-check the sample team compositions and the tier list on GameVika before sinking resources in.

These are the mistakes that sink players who otherwise have good Agents:

• Skipping the Stable/Disputed Nodes. They're one-time rewards that never reset — plenty of players jump straight to the Critical Node and leave several thousand Polychrome sitting there.
• Building only one team. The Critical Node needs 6 Agents and 2 Bangboo. Pouring everything into your first four Agents walls you off from your own progress.
• Missing the reset. The Critical Node resets every two weeks; not clearing before the cutoff means that cycle's Polychrome is simply gone — nothing carries over.
• Letting Inter-Knot Level lag. Your Agents' level cap is gated by your Inter-Knot Level — a team that's weak because it's hitting the level ceiling can't be fixed with better gear.
• Dumping Ultimates before the Stun. The damage lands into armor instead of the Stun window: the clock keeps running while the HP bar barely moves.

Once Shiyu Defense feels routine, the next step is Deadly Assault — which demands three fully separate teams — and Hollow Zero if you prefer map-based exploration.