Yokai Weapons are special weapons in Nioh 2. Yokai Weapons can be found for any of the in-game weapon categories, and are obtained by defeating Yokai Enemies in game. They have special properties, but are also corrupted by the Yokai Realm.
What is a Yokai Weapon
Yokai weapons are imbued with Corruption and build up the Corruption Status Effect on those it is used against. Enemies that are inflicted with the Corrupted Status Ailment receive 35% increased Ki damage which is absorbed by their attacker.
What do Yokai Weapons do?
When you inflict damage on an enemy with a Yokai Weapon or Yokai Ability, your Sentience Gauge will build up. When it fills completely, you will achieve an Awakened State, during which your weapon's power will be enhanced - It multiplies your melee damage by 30% and the last attack of a strong attack string will also shoot a corruption-imbued sword beam.
When it awakens you also hear the thoughts of the Yokai weapon up to 5 times based on your familiarity tier with the weapon. You will need at least an exotic version of the weapon to be able to hear all 5 thoughts.
List of Fixed Yokai Weapons
Note that any weapon that doesn't have a fixed imbue element effect can be a Yokai Weapon if they drop with Imbue Corruption on it. These weapons also have one of two generic voice lines:
Blood... More blood... I need more!
That's right! Cry! Scream! And then die! Ha ha ha!
Ha ha ha! More blood! More guts! MORE!
Ha ha, you're a feisty one! Come on, keep swinging for me...
Keep swinging! Kill every last one of them! Ha Ha!
Yes, yes... I'll kill 'em all! Hee hee hee!
The color of blood, the crimson glow... Magnificent, is it not?
It's still not enough.. Give me more blood!
I want to bathe in their blood! Hee hee hee!
More, more, more! I want to kill more!