How to defeat Sirene in Clair Obscur Expedition 33

Sirene in Clair Obscur Expedition 33 is one of the two Axons you must defeat to reach The Monolith in Act 2 of the campaign. It is a mandatory boss with many tricks up its sleeve. However, there are a few things you can do to counteract it. While you can tackle the two bosses in any order, Sirene is a tad easier to fight.

This article guides you on defeating the titular Axon in Expedition 33.

Note: The article contains spoilers for game and story elements up to Act 2 of the campaign.

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A guide on defeating Sirene in Clair Obscur Expedition 33

Starting the fight against Sirene in Clair Obscur Expedition 33 (Image via Sportskeeda Gaming || Kepler Interactive)

• Weaknesses: Dark and Ice
• Resistances: Light and Earth

The first important thing to note in the fight is that whenever you want to damage Sirene through your Free Aim mechanic, target the purple-ish smaller creature, not the puppet.

Another important step before fighting Sirene in Clair Obscur Expedition 33 is defeating the optional Tisseur boss. If alive, it will occasionally provide Sirene with Shields, adding additional obstacles to the fight along with disabling the Anti-Charm Pictos if you already have it.

Defeating Tisseur will give you the Anti-Charm Pictos; make sure to master its Lumina and equip it on all members since Sirene has two major attacks that apply the Charm status effect.

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Party composition

Sciel and Monoco are excellent members for the fight against Sirene in Clair Obscur Expedition 33 due to their ability to dish out massive single-target Dark damage. Verso can also be used here if you're acquainted with maximizing his damage output through his Perfection mechanic. Finally, if you're familiar with using Maelle's Virtuoso Stance, she can be another great damage dealer for this fight.

These skills are the best for the fight against Sirene in Clair Obscur Expedition 33:

Sciel:

• Doom
• Marking Card
• Phantom Blade
• Final Path

Monoco:

• Obscur Sword
• Mighty Strike

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First phase

The first phase (Image via Sportskeeda Gaming || Kepler Interactive)

Sirene in Clair Obscur Expedition 33 has a lot of attacks, each with different defensive measures, so it's better to dodge here since its timing will be more lenient.

Here are the attacks she can do in the first phase:

• "Sirène dances with the Glissandos.": She'll summon two Glissandos, slamming one a single time. This attack hits the entire party. Dodge it when you see her hand going down.
• "Sirène attacks with her dress.": Sirene will summon three patches of a green cloth with brown edges and attack with them once. The first one will attack the middle member, the second one will attack the right, and the third one will attack the left. The second and last attack will come out quicker, so be attentive.
• "Sirène seduces [a party member's name].": The boss will surround a party member with ribbons. This will be a Gradient Attack, so use a Gradient Counter immediately when you see the color draining from the screen.
• "A widow Ballet Charms [a party member's name] and flies away.": Sirene will summon a widow Ballet dancer who'll summon an energy orb. It will only be visible when it pulses, which it will do thrice. Dodge during the final one. Follow the rhythm, since this attack comes out quickly.

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Phase two

Sirene during her second phase (Image via Sportskeeda Gaming || Kepler Interactive)

Cut down one-third of her health, and the second phase will begin with the phrase "Sirene's dance becomes frantic." She'll introduce one new attack:

• "The Grand Ballet begins": Sirene will introduce five different ballet dancers who can deal different elemental damage to each of their attack connects. Each dancer will go to the right of the screen and swoosh to the left. The gap between the first four dancers will be the same, but the last attack will have some delay.
• "Sirène summons two Glissando that shakes the ground.": The boss will call two Glissandos to disrupt the ground. Jump after the yellow jump sign disappears, then quickly parry.

Keep chipping at her health, and Sirene in Clair Obscur Expedition 33 will eventually enter the final phase.

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Phase three

Sirene during her third phase (Image via Sportskeeda Gaming || Kepler Interactive)

Here are all the attacks added with the phase shift:

• "The Final Act begins.": Sirene will summon one Glissando on the left side of the screen, widow dancers on the right side, and a giant building above. A single round consists of her slamming a Glissando, causing a shockwave you need to jump over, followed immediately by an attack with the widow dancer. She'll do a total of three rounds, and then finally slam the building on the ground. Jump over the Glissando when the jump symbol disappears and parry when the ballet comes towards you. Finally, parry the building slam when you see it hurling towards you.
• "Sirène is enraged and slams the ground": The boss will put a three-punch combo, Parry/dodge when you see each attack hurling towards you.

Keep dodging and parrying her attacks while exploiting her weakness to defeat Sirene in Clair Obscur Expedition 33.

Defeating the titular boss will reward you with the following:

• Tisseron, a weapon for Sciel
• Energizing Turn Pictos
• Resplendent Chroma Catalyst x3

That was all about fighting Sirene in Clair Obscur Expedition 33.

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Check out our other articles on the game:

• Is Clair Obscur Expedition 33 coming to Nintendo Switch and Switch 2?
• 7 best RPGs to play while waiting for Clair Obscur Expedition 33
• Is there Romance in Clair Obscur Expedition 33?
• How to fast travel in Clair Obscur Expedition 33
• Clair Obscur Expedition 33 update 1.2.2: Everything new added with the latest patch (April 29, 2025)