The Siphon: what it is and when it triggers
Shidou and Nue break the pattern most other duo Nushi fights set up. Earlier pairs come down to element-matching and clean parries with no second layer on top; this one adds a genuine third mechanic. When Shidou's own health drops to roughly 30%, he stops attacking, extends a Blight branch onto Nue Malefact, and channels Nue's HP directly into his own bar until you interrupt him. Two independently tested guides converge on that ~30% figure, and it isn't a fresh heal pool — it's HP moving out of Nue's bar and into Shidou's, which matters for how you should react to it.
At a glance
| Detail | Info |
|---|---|
| Weakness | Poison — both bosses share it |
| Encounters | Chapter 3 (Lv.20), Chapter 6 (Lv.35), Chapter 11 (Lv.48) |
| Key mechanic | Siphon — Shidou drains Nue's HP into his own near ~30% health |
| Best interrupt | Rush Shidou with Nushi skills the instant the Blight branch attaches; staggers both bosses at once |
| Recommended prep | Poison arrows/bolts, a Poison-aligned sword, sustain-focused armor |
| Third-fight reward | Bloom Art: Erica Strangle Lv.1, Blade Art: Nue Lv.1, and the Black Blossom sword (per one tested source — treat as not confirmed against our own boss table, which lists the pair's Nushi Skill as Chimeric Flow from the Chapter 3 fight) |
Should you let the Siphon complete?
Yes, at least once or twice. Since you have to bring both bosses' health bars down to zero eventually, a completed Siphon cycle is damage you didn't have to land yourself — it just moves HP from a bar you're already draining into one you also need to drain. The practical line tested across guides: let Shidou drop to around 30%, ease off and allow two or three drains to run, and only start interrupting once Nue is also getting close to that same 30% mark. Past that point, every additional Siphon cycle is progress you're giving back, so switch to rushing Shidou with Nushi skills as soon as the Blight branch attaches — that stagger hits both bosses simultaneously and cancels the drain outright.
One wrinkle worth knowing before your first pull: tested attack tables list the Siphon (sometimes called "Health Absorb") explicitly under the Chapter 6 encounter, which implies it may not be present at Chapter 3, while a separate walkthrough source says Shidou has it from the very first fight with only the damage scaling up later. The sources don't agree on when it starts — only on how it works — so watch for the Blight-branch tell from your very first pull at Level 20, and don't be alarmed if it doesn't show up until the Chapter 6 rematch.
The Poison loadout
Both bosses share one elemental weakness — Poison — confirmed consistently across every tested guide. That simplifies gearing, but sequencing the fight still matters more than the element itself:
- Stock Poison arrows or bolts before walking in; ranged poison procs keep ticking during Nue's aerial openings, where melee can't always reach.
- On Koo (for the Chapter 6 and 11 fights, where he's present), lean on a poison-type Bloom Art if you've unlocked one — see our Koo guide for how Bloom Arts slot into the FP economy.
- Bank at least one full FP bar before pushing Shidou toward 30%, since FP only fills off clean parries and Bloom Arts can't fire back-to-back — an empty bar when the Siphon triggers means watching it complete with no way to interrupt it.
- Sustain-oriented Spirit Stones matter here too; our builds guide covers the stat and gear tradeoffs across all four build directions if you need to retool before this fight specifically.
Attack patterns and parry timing
The two bosses take turns attacking rather than truly overlapping, and the game's auto-lock tends to follow whichever one is about to swing next — resist the urge to manually flip targets mid-combo, since it can cost you a dodge window for nothing.
| Attack | Boss | Counter |
|---|---|---|
| Two Slashes | Shidou | Parry each swing |
| Blight Combo (2 long swings) | Shidou | Parry, roughly 1.5s apart |
| Blight Lunge | Shidou | Dodge only — not parryable |
| Tree Slam | Shidou | Perfect-dodge before impact — unparryable |
| Giant Leap / Pounce | Nue | Dodge just before it lands |
| Claw Combo (5-6 hits + slam) | Nue | Parry every strike |
| Tail Spin | Nue | Parry, roughly 2s apart |
| Lightning Strikes | Nue | Unparryable — dodge repeatedly |
| Siphon (Blight branch) | Shidou | Rush and hit with Nushi skills to stagger both |
The single biggest positioning mistake in this fight is standing between the two bosses — it puts you in range of an attack from whichever one is behind you, which is the easiest way to eat a hit you never saw coming while you're already tracking two movesets and one drain mechanic.
The three encounters: what changes
Chapter 3 (Level 20) — first pull. Treat it as a practice rep for parry timing; sources disagree on whether the Siphon is even active this early, so don't panic if you don't see the Blight-branch tell.
Chapter 6 (Level 35) — rematch. This is the encounter where the Siphon is consistently confirmed active, and Nue's Charged Combo adds a lightning circle on its second strike. Damage scales up across the board, so bank a full FP bar before engaging.
Chapter 11 (Level 48) — final fight. Nue adds a Seed Bomb to its kit, and per one tested source this is the encounter that pays out gear (see the table above) — treat the exact reward as not confirmed against our own boss list until we can verify it directly. Story pacing means you'll rarely reach any of these three fights badly underleveled; if you are a couple of levels short, clearing more of the previous chapter's side content is generally more efficient than trying to out-damage the gap.
Common mistakes
- Panicking and interrupting every Siphon cycle. Early drains against the boss you're already killing are free progress — save your interrupt for when Nue is close to 30% too.
- Fighting with an empty FP bar. If you can't spend FP the moment the Blight branch attaches, you're stuck watching the drain finish.
- Manually swapping lock-on targets mid-combo. The auto-lock already follows whichever boss is about to attack; fighting it costs you a dodge window.
- Standing between the two bosses. You'll eat a hit from whichever one is out of frame.
Shidou and Nue FAQ
Should I try to prevent the Siphon entirely?
No — letting it fire once or twice against Nue's health bar is generally faster than blocking it every time, since that damage has to be dealt eventually regardless of which bar it comes off. Start blocking it only once Nue is already near the 30% mark.
Do I need different gear for the second and third encounters?
Not fundamentally. Poison stays the correct element across all three fights; only the incoming damage numbers scale up. FP management matters more in the later fights, since the combos hit harder and you need a full bar ready to punish the Siphon.
Is the Chapter 3 fight worth grinding for loot?
Available data suggests no meaningful reward comes from the Level 20 or Level 35 pulls, with any gear payout arriving at the third encounter instead. Treat the first two fights as practice reps.
Why does my target keep switching mid-fight?
That's intentional — the two bosses take turns attacking, and auto-lock follows whichever is about to swing. Fighting it by manually flipping targets is more likely to cost you a dodge window than help.
Related guides
- All bosses — Malefacts & Nushi, in order
- Koo commands & skills, explained
- Builds & skill trees
- Crimson Malefact boss guide (the fight without Koo)
- Nushi Skills — where Chimeric Flow comes from
Sources
- Switchblade Gaming — Shidou and Nue Boss Guide (Siphon mechanic, attack table, per-encounter breakdown)
- Sportskeeda — Shidou and Nue boss guide (weakness confirmation)
Last reviewed: September 10, 2026 · The exact Chapter 11 reward list is cross-checked against one source only and marked not confirmed until verified directly against our own boss table.