Infernal Rouge.

When Soul Tempering reshapes Sanguine it becomes Infernal Rouge, a fabled Bastion of Mó arm built to cheat death and then turn the bonus minutes into offence.

You still wield it in one hand as a main weapon, but Sanguine's simple set of moves is replaced by three connected mechanics. A passive revival shields you from a single lethal blow, an active awakening changes how all your attacks work, and a finishing strike spends that awakening. Sanguine only asks that you keep pushing forward; this blade makes you judge how much danger the current battle justifies.

In terms of progression it belongs at the very end. Its material shows up only after the Long Pillar chain concludes in Mirage Estate, the penultimate area of the game, so you equip it for the closing section or for roaming after the credits. Blazing Edge is the family's other Soul Tempered weapon, but it is a two-handed blade centred on fire and a charged strike, whereas this one-handed weapon is about staying alive while remaining aggressive.

Because Phantom Blade Zero has no published 0–100 bars for stats, this page gives the weapon's numbers as they stand at level 1.

These numbers are taken from values the game itself lists for level 1; they were not confirmed through play.

Before you start:

• Possess Sanguine, a weapon Soul begins the game with
• Have already encountered Myst in Pangzhen
• Get to Mirage Estate using the Hunter's Chain Sickle
• Finish the remaining Long Pillars, leaving this final fight as the one that awaits

1. Talk to Myst at Myst’s Tavern in Pangzhen. Doing so opens up Soul Tempering, and the main route leads you to her anyway.
2. Complete The Four Serpent Houses to get into Mirage Estate; the door behind the Green Serpent House opens as a result.
3. Rest at the Covered Corridor Bell, move ahead and stay to the right until a grapple point appears below you, then cross over to the Mirage Estate Lóng Pillar with the Hunter's Chain Sickle.
4. Approach the dragon statue and use it. Mó Yuan must then be beaten in the last Long Pillar battle, which rewards you with the Bastion of Mó Mask.
5. Pay the mask and 5,000 Remnant Dust to Soul Temper Sanguine, which turns it into Infernal Rouge.

Besides the Standard Combo and Sha-Chi Combo, the weapon gains three original moves. Think of them as one chain, although nothing forces you to use them in that order.

What Bloodline Rebirth costs

Lethal damage sets this off automatically. You get a full HP refill and a rise in Attack, but from then on HP drains steadily and active healing is impossible. The state finishes after the drain has taken away a fixed amount of HP.

Once used, the rebirth is unavailable until you reach a Bell or die and respawn, which means one activation per span between Bells. Other revival effects you carry are kept in reserve, because this one goes off before them.

Bloodline Awakening and the Phantom Soul

Paying a single Sha-Chi point stirs the bloodline and turns Soul into the Phantom Soul for a brief time. Attack and Defense climb steeply, and a blade wave is released with every strike, extending the range of normal combos. The buff runs out, so activate it only when you have a safe opening to attack.

The awakening closes with Phantom Blade

You can use Phantom Blade solely while Bloodline Awakening is active; it consumes one more Sha-Chi point and sends out a sky filled with crossing blade light. Guarding cannot stop it, but the awakened state ends once it is used, so save it for the last moments of the state or for when this single hit will settle the battle.

Inherited from Sanguine

Sanguine's unlock list is repeated here, namely Chi-Infused Blade, Phantom Execution across three ranks, Drifting Clouds and Flowing Water. Players familiar with the base weapon will recognise this portion of the kit.

Perks from levelling

Every upgrade lifts the weapon by one level, and these moves and passives become available at the levels listed.

Materials for upgrading

Upgrading draws on Sanguine's metal and solvent series, yet in the early and middle stages the quantities are bigger and extra Remnant Dust is charged beyond what Sanguine demands. Spent materials come back through reforging, and the process is said to cost nothing through Level 10, then to need a talisman beyond that.

Strengths

• At the very moment an error would have ended your attempt, Bloodline Rebirth restores your HP in full.
• Because Bloodline Awakening lifts Attack as well as Defense, it is useful when exchanging hits and not just when you are on the offensive.
• While awakened, a blade wave accompanies every strike and lengthens the reach of regular combos.
• Raising a guard will not stop Phantom Blade, since it cannot be blocked.

Weaknesses

• HP drains throughout Bloodline Rebirth and cannot be actively recovered, which puts a clock on the extra life.
• Once used, the rebirth stays unavailable until a Bell is touched or you respawn.
• Using Phantom Blade terminates the awakening, so you give up what is left of the buff for a single heavy strike.
• It is obtained when the Long Pillar chain is nearly over, so very little of the plot is left for you to use it.

Best used for

• Extended boss attempts in which living through a lethal hit matters more than dealing extra damage.
• Battles that offer a safe gap for activating Bloodline Awakening and benefiting from its raised stats.
• Exploration at the end of the game, and battles remaining after the credits.

According to its item description, this is a legendary Bastion of Mó weapon concealing secrets about Soul's origins, and the powers it can activate are named as Bloodline Rebirth and Bloodline Awakening.