This is a madougu from Mikagami's Family. It is because of this madougu that Tokiya lost his precious sister. Ensui's fundamental source of power comes from water. It can turn into a sword of water which can be very sharp. Usually, the technique that Tokiya uses is called Hyomon Ken and it has the following techniques:
It this stage, the water is used to produce a false image so that Tokiya can go somewhere to attack. This is frequently used and can be quite deceptive. Koganei are taken by surprise by this technique.
This is to use ice to freeze whatever object. It is at 0 Kelvin so that any life activity will be stopped immediately.
This is when Tokiya sticks ensui into the ground and freezes the ground so that pillars of ice will emerge from beneath to destroy the enemies and take the enemies by surprise
The Snake of Water
This is to form water bublles from the four corners of the world and then turn these water bubbles into a snake like wave that can attack the enemies.