Where to Find and How to Beat All 9 Invasive Monsters in Monster Hunter Stories 3: Complete Guide

In Monster Hunter Stories 3, players will need to track down and defeat nine Invasive Monsters. Since they stand between you and the world’s vanishing species, you’ll almost certainly want to take them on during your journey.

We’ll tell you where to find every Invasive Monster and how to beat each one for the first time, including the special conditions you must meet to win and a quick rundown of each fight.

What are Invasive Monsters in Monster Hunter Stories 3?

Invasive Monsters are powerful creatures that have seized territory belonging to vanishing species. They’re stronger than regular members of their kind and often wield unique attributes and attacks.

You’ll need to defeat nine of them in total. The first time you meet one, you’ll have to meet a few conditions to drive it off. After that, it retreats to the Vanishing Species Den, where you can enter and find a rare monster egg.

Inside these dens the Invasive Monsters are dormant. When you feel ready for the final showdown, interact with them inside the den to start a Decisive Battle and try to slay the monster for good.

This guide focuses on where to locate each Invasive Monster and the conditions you must meet to beat them the first time. The list includes:

Invasive Yian Garuga
Invasive Plesioth
Invasive Seregios
Invasive Arzuros
Invasive Nerscylla
Invasive Shogun Ceanataur
Invasive Diablos
Invasive Odogaron
Invasive Khezu

How to beat every Invasive Monster in Monster Hunter Stories 3

How to beat Invasive Yian Garuga

Location: Azuria: Sun-Petal Plains
Win Condition: None
Element: Fire
Attack Type: Technical

You’ll naturally run into Invasive Yian Garuga after setting up your first camp in Azuria. Look for it in the rocky terrain on the eastern side of Azuria.

As your first Invasive Monster, Invasive Yian Garuga isn’t too tough. When it enrages, it starts preparing a powerful attack. All you need to do is focus every attack on breaking its legs.

If you break them before it unleashes the big hit, Invasive Yian Garuga will trip and crash mid-attack. After the tumble it promptly flees the field and retreats to the Vanishing Species Den. Grab the egg there and hatch it back at camp to discover it’s a Rathian.

How to beat Invasive Plesioth

Location: Azuria: Mirror Lake
Win Condition: Monstie with a Fire attack
Element: Water
Attack Type: Technical

You’ll find Invasive Plesioth in a hidden cave on the northern edge of Mirror Lake, swimming laps around the stone pillar in the center of the cavern.

The key to beating the Invasive Plesioth is to bring a Monstie with Fire-element attacks. At the start of the fight your strikes won’t hurt it at all, so just focus on staying alive.

When the Invasive Plesioth enrages, order your Fire Monstie to hit its head with a Fire-element attack. The easiest way is to have Rath use the skill “Inferno Fireball.” After the blast the Plesioth will try a water attack, fail, and flee the area.

Its retreat spawns a new Ephemeral Den in the same cave; the egg inside gives you your first Lagiacrus Monstie.

Catching this ephemeral Monstie is mandatory for completing the quest “An Adventurer’s Soul State.”

How to Defeat the Invasive Seregios

Location: Azuria: Mirror Lake
Win condition: A hammer skill that hits every enemy.
Element: None
Attack type: Technical

To reach the Invasive Seregios, ride an updraft at Mirror Lake and land on the hill in the north-west corner of Azuria. Head toward the corner and you’ll enter a wide clearing where the Invasive Seregios is patrolling.

Like other Invasive monsters, your first attacks won’t damage it; concentrate purely on dodging and raising your defense.

When Seregios enrages it opens with a heavy-hitting normal skill. What matters is the moment it uses “Invasive Acceleration Roar” to prep its Scale attack. The roar produces a colored spark in front of it, showing which type of attack it will use.

Seregios will clash with you using that attack.

To win the clash you must use a hammer skill that damages every enemy and whose type beats the one shown by the spark. For example, if a blue spark appears, use a Technical skill like “Crushing Blow.”

If you fail the first time you get an immediate second chance. Winning the clash makes Seregios flee and creates another Ephemeral Den; the egg inside is Astalos.

How to Defeat the Invasive Arzuros

Location: Canalta: Blessing Hill
Win condition: None
Element: None
Attack type: Power

You’ll find the Invasive Arzuros along Canalta’s southern border. Since defeating it is part of the main story, following the orange quest markers will lead you straight to it.

As the second Invasive monster you face in the story, Invasive Arzuros has no special conditions and is fairly easy. The goal is to make it run out of honey, forcing it to retreat. Keep knocking out the allies it calls with its honey and you’ll achieve this quickly.

After driving off the Invasive Arzuros and following it into its Vanishing Species Den, you’ll find a Kanyne egg. Bring it back to Shepardon to hatch the first Kanyne Monstie anyone’s seen in ages—your very first partner that can burrow underground.

How to Beat the Invasive Nerscylla

Location: Canalta: Blessing Hill
Win condition: Gunlance with the skill “Wyvern’s Fire Breath”.

Element: None
Attack type: Technical

The Invasive Nerscylla hangs out on the clearing near the south-east edge of Canalta Forest. Reach it by leaping the river up to a high ledge; the spot’s easy to spot if you fast-travel to the Catavan stand on Blessing Hill and head east.

Its trick is turning invisible, so your attacks whiff. While you can’t hit it, focus on building enough stamina to fire the Gunlance skill “Wyvern’s Fire Breath.” Chow down on a ration or any stamina item to top off quickly.

When the Invasive Nerscylla roars and enrages, it starts throwing out heavier hits. Wait until it locks on to you and a red line appears between you on the field. That line means it’s about to use “Invasive Death Scissors,” an instant-KO move.

As soon as you see the line, hit it with “Wyvern’s Fire Breath.” The blast sets it ablaze and it flees. Chase it back to its den to score a Nargacuga egg.

How to Beat the Invasive Shogun Ceanataur

Location: Canalta Forest: Ice Grotto
Win condition: Items or skills that spike your defense—ideally “Dragon Mega-Armor.”
Element: Water
Attack type: Power

The Invasive Shogun Ceanataur lurks in the hidden second half of the Ice Grotto near the Haouliolio Forest Overlook.

The entrance is tucked behind the waterfall in that area.

Before the fight, stock up on defense-boosting items. You’ll want every point you can get, so craft or find Dragon Mega-Armor.

The recipe for Dragon Mega-Armor is the reward for the third quest given by the girl next to the Canalta Forest waterfall camp.

When the Invasive Shogun Ceanataur extends its claws, it will single out one party member. Immediately pop Dragon Mega-Armor on that target. When the Shogun attacks, the blow will bounce back, damaging the monster and forcing it to retreat.

The retreat spawns a Vanishing Species Den inside the cave. Hatch the egg there to claim your first Mizutsune.

How to Beat the Invasive Diablos

Location: Tarkuan: Colossal Dragon Remains
Win condition: Hammer with a meteor skill; we used “Meteor Hammer.”
Element: None
Attack type: Power

The Invasive Diablos can be found in the south-eastern corner of Tarkuan. To reach it, climb to the top of the Colossal Dragon Remnants and head to the eastern edge. From there, glide east toward the boundary and land on the ledge that leads to the Invasive Diablos area.

Before you set off, make sure one of your weapons is a hammer with a Meteor skill. We used “Meteor Hammer,” but any strong hammer skill with “meteor” in the name will do.

As always, the first priority in the fight is staying alive. Keep an eye on your stamina—you’ll need enough to use the hammer’s Meteor skill.

The key moment comes when the Invasive Diablos triggers “Invasive Spiral Ambush.” During this move it shuttles between three burrows; dust and stones spout from a burrow each time it dives in.

Track its movements and time your Meteor Hammer strike so the meteor hits the burrow just as the monster passes through. You must attack with the Speed attribute or you’ll miss even if the Diablos is in the chosen hole.

A successful counter will send the Invasive Diablos retreating. Follow it back to its den to claim a Tigrex egg.

How to Defeat the Invasive Odogaron

Location: Tarkuan: Rokoko Rox
Win condition: A Monstie that can inflict Mud Mire, e.g. Almudron.
Element: None
Attack type: Speed

The path to the Invasive Odogaron lies west of the Cathavan stop in Rokoko Rox. You can just barely reach the western ledge by jumping off the platform and gliding, but it’s easier to ride the highest updraft in southern Rokoko Rox and then glide across.

Before you go, make sure you have a Monstie that can apply Mud Mire. The simplest choice is Almudron; any of its skills that “sets a trap dealing continuous water damage” will inflict Mud Mire.

You can’t stop the Odogaron the first time it enrages and uses “Invasive Crimson Claws.” From that point on, keep Mud Mire active on it for as long as possible. It is crucial that the status is up when the prompt “Focus on the claw attack!” appears.

While Mud Mire is active, the Odogaron’s “Invasive Crimson Claws” becomes “Crimson Claws (no fire).” It will attempt the move twice; if both are nullified by Mud Mire, the Invasive Odogaron flees.

The egg found in this Vanishing-Species Den belongs to Zinogre.

How to Defeat the Invasive Khezu

Location: Seralta: Icy Peaks
Win condition: Paralysis-healing powder or other items that cure and prevent paralysis.
Element: Thunder
Attack type: Technical (normal); Power (enraged)

The Invasive Khezu is on the meadow to the right of the camp in the Icy Peaks. Climb to the top of the Icy Peaks Overlook and glide toward the meadow. Aim to land on one of the taller, ice-free stone pillars; you’ll need to hop from pillar to pillar to reach the meadow.

Before the fight, stock up on items that cure paralysis and grant paralysis immunity. Beating the Invasive Khezu requires coordinated attacks with your Monsties, which becomes nearly impossible if party members are paralyzed.

It’s also wise to eat a meal that boosts the Kinship gauge—you’ll need to use a Kinship skill at a critical moment.

Your goal in the first part of the fight is to keep your team from being paralyzed and to use joint attacks. When Invasive Khezu is about to cast “Thunder Zone” and paralyze your team, Rudy will warn you so you have time to use a protective item.

Once the words “Wyvern Blast charged” appear on-screen, Khezu will try to clash head-on with either you or your Monstie. Your objective here is to win that showdown with a joint attack. In this state Khezu uses Power attacks, so you need to hit it with a Speed-based joint attack.

After Invasive Khezu is weakened by your joint attacks, your teammates will start saying he looks hurt. This marks the beginning of the next phase.

After another turn or two, the words “Tutorial complete” will show up, and Rudy will note that Khezu is acting as if it knows your next moves. In the final stretch of the fight you’ll need to use your Kinship Skill when the corresponding signal appears. It might be a line like “Can the power of kinship stop him?” or a hint that you should try something new to halt Khezu.

The moment that line appears on-screen, immediately attack Invasive Khezu with your Kinship Skill. The battle will seem to continue as normal, but Khezu will flub its next attack and flee to the Disappearing Species Den. The egg you get from that den belongs to a Barroth.

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