To get a Soulseer Mizutsune Egg, you first need to update Monster Hunter Stories 2: Wings of Ruin to 1.3.0. Once that has been completed, you need to interact with A Quest Board in any village and click on Multiplayer.
Click online play, navigate to the Expeditions tab, and locate the quest (Explore) Water Eggs. This is an 8 Star quest and is easier to do online over co-op with a friend or a randomer. You can do it solo and be given an AI friend to help, but the AI companion is useless compared to a real-life person.
Once the quest is selected, press OK, choose your Expedition Ticket. We recommend using an Expedition Ticket SR, as this gives a higher chance of acquiring a deviant style egg, or in this case the Soulseer Mizutsune egg, but there is no guarantee.
Explore the area, and locate Soulseer Mizutsune's den. If you don't want to fight anything on your travels, bring along a Nargacuga and use its Stealth monster ability not to get aggroed by any monsters. You'll get to your destination in peace.
Soulseer Mizutsune is not an easy fight. Though the monster has no eyes, it will cloak itself in its own bubbles and will counterattack every move against it. It has massively damaging Area of Effect moves, so if you go in underleveled or unprepared, your three hearts may be gone in a hail of bubbles. Use the table below to help.
|Monster||Attack Type||Counter||Element Weakness||Physiology & Parts Weakness|
|Soulseer Mizutsune||Initial: Speed|
When Soulseer Mizutsune has been defeated, you can then loot the nest for eggs. Due to Soulseer being a deviant, the egg alters slightly from its base form. Use the picture below to know exactly what egg you are after—the egg is slightly more purple than the non-deviant egg.
Like normal, walk towards the exit of the den with your prize and make sure the egg is stored. Then go and hatch it to see if you were lucky enough to get Soulseer Mizutsune as a Monstie. If not, rinse and repeat.