Genshin Impact Millennial Pearl Seahorse Boss Guide: Location, how to beat it, best team comp, and more

A screenshot of the Millennial Pearl Seahorse from the Genshin Impact 4.1 Livestream.
Credit: HoYoverse

A screenshot of the Millennial Pearl Seahorse from the Genshin Impact 4.1 Livestream.
Credit: HoYoverse

The launch of Version 4.1 brings a plethora of new challenges to Genshin Impact, including the elegant yet deadly Millennial Pearl Seahorse. Much to the delight of fans, this update has also unveiled a brand-new underwater area, where the Millennial Pearl Seahorse can be found.

Due to the influence of Arkhium, this new underwater area has a peculiar ecosystem which is home to a host of hostile creatures. Among them is the formidable Millennial Pearl Seahorse. This apex predator has evolved from the once-adorable Bubbly Seahorse and now prowls the depths.

Here, you'll find a comprehensive Millennial Pearl Seahorse boss guide covering everything you need to know about the new boss of Version 4.1, including its location, strategies for defeating it, rewards dropped upon its defeat, and more!

Millennial Pearl Seahorse location

With the launch of Version 4.1 comes a new underwater area for players to explore! Within this watery domain resides the elusive Millennial Pearl Seahorse.

A screenshot of the Millennial Pearl Seahorse location from the Genshin Impact Teyvat Interactive Map.
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Credit: Teyvat Interactive Map

You can locate the Millennial Pearl Seahorse in the northern section of the Liffey region's underwater expanse. As you venture into the area, you will come across a large entrance to an underwater cave. At the end of this cave lies the Millennial Pearl Seahorse.

A screenshot of the Millennial Pearl Seahorse from the Genshin Impact 4.1 Livestream.
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Credit: HoYoverse

According to Fontaine's ancient legends, a brutal war once raged among the Aberrants of the Fontemer. This explosive conflict left behind only two sovereigns: the "Millennial Pearl Seahorse" and the "Emperor of Fire and Iron". It resulted in the division of the Great Lake into two courts, one reigning over the North and the other over the South.

Millennial Pearl Seahorse attack patterns

There are also a couple of attack patterns you should watch out for when fighting against the Millennial Pearl Seahorse. Here are all the attacks we know so far:

Shock Dive

A screenshot of the Millennial Pearl Seahorse's attack from the Genshin Impact 4.1 Livestream.
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Credit: HoYoverse

In this move, the Millennial Pearl Seahorse gracefully leaps into the air before swiftly diving back to the ground. Upon landing, it unleashes a devastating AoE Electro attack. To evade this, observe the Seahorse's jump animation and move out of the way in advance.

Electro-Homing Missile

A screenshot of the Millennial Pearl Seahorse's attack from the Genshin Impact 4.1 Livestream.
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Credit: HoYoverse

The Millennial Pearl Seahorse takes aim and launches electro-homing missiles toward the player's position. To avoid this incoming attack, promptly dash to safety before the missiles make contact.

Electro Charge Attack

With a pointed horn adorning its head, the Millennial Pearl Seahorse charges straight ahead in a lightning-fast attack. This attack is much faster than its other attacks. However, players can dodge it by simply sidestepping with a quick dash.

Thunder Strike

iA screenshot of the Millennial Pearl Seahorse's attack from the Genshin Impact 4.1 Livestream
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Credit: HoYoverse

In this powerful move, the Millennial Pearl Seahorse channels lightning through its horn, culminating in a large-scale strike. Prior to the onslaught of lightning, you'll notice a marked area expanding within a circle. To steer clear of the impending attack, leave the designated zone as quickly as you can.

Alternatively, you can disrupt the channelling process by destroying the three Resonant Coral Orbs on the ground.

How to defeat the Millennial Pearl Seahorse

Having transformed into a fantastical creature, the Millennial Pearl Seahorse now boasts the Xenomare Pearl beneath its head — a crystallisation of Electro, granting it the ability to unleash even more potent elemental assaults and bolstering its defences. The Millennial Pearl Seahorse gains most of its power from the Xenomare Pearl.

However, it is also its most vulnerable point. To severely weaken the Millennial Pearl Seahorse, target the Xenomare Pearl with elemental reactions and destroy it.

A screenshot of the Millennial Pearl Seahorse's attack from the Genshin Impact 4.1 Livestream
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Credit: HoYoverse

On top of that, when the Millennial Pearl Seahorse performs its Thunder Strike attack, it will generate Resonant Coral Orbs on the ground. Seize this opportunity and destroy these orbs to inflict significant damage to the Xenomare Pearl.

Best team comp for Millennial Pearl Seahorse

In its normal state, the Millennial Pearl Seahorse boasts a formidable 60% resistance to Electro, but exhibits only a 10% resistance to other forms of damage, including physical attacks. When shielded by its pearl, its elemental resistances surge by 60%, adding an extra layer of challenge to the battle.

Select Pyro or Cryo units as your primary DPS and Sub-DPS to leverage a wide array of elemental reactions. To optimise your combat effectiveness against the Millennial Pearl Seahorse, focus on generating Overload and Superconduct reactions.

We highly advise including DPS archers in your team comp, as the boss constantly hovers above the ground, becoming inaccessible to those who use melee weapons. Archers can also easily target the Millennial Pearl Seahorse's weak spot: its Xenomare Pearl.

For your team composition, here are our suggestions on who you should add to your party when taking on this boss:

  • Yoimiya, Xingqiu/Yelan, Yun Jin, Diona
  • Lyney, Xiangling, Kazuha, Bennett

Don't fret if you do not have a strong Pyro DPS character, as the Millennial Pearl Seahorse does not possess any notable elemental (aside from Electro) or physical resistance, feel free to employ the team you’re most comfortable with and you are good to go.

Millennial Pearl Seahorse drop rewards

Upon defeat, the Millennial Pearl Seahorse will drop the Fontemer Unihorn. Currently, only the revered Chief Justice of Fontaine, Neuvillette, requires the Fontemer Horn for Ascension.

A screenshot of a new Fontaine Boss in Genshin Impact Version 4.1: Millennial Pearl Seahorse
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Credit: videreleaks
New Fontaine Boss in Genshin Impact Version 4.1: Millennial Pearl Seahorse

That's all you need to know about the Millennial Pearl Seahorse boss fight!

Interested in learning more about Fontaine? We've got you covered. Dive right into our Version 4.1 overview, and our guide on all the much-needed QoL changes coming to Version 4.1. We have also gathered all available information regarding the upcoming Version 4.2 update, including release date, potential banners, and more!

Discover all that you need to know about the 18 new Fontaine characters. On top of that, the 4.3 banners have been leaked! Get ahead of the curve and start planning your Primogem savings for your favourite Fontainian characters with our Fontaine character banner schedule here.