Beast that lies in the dark

1. Summoning: When the user snaps their left middle finger, and chants “Act 1” a small Nen beast (using emission and conjuration) is summoned and controlled using manipulation. The Nen-Beast is invisible to humans who cannot sense Nen (As a fundamental ability of Nen constructs) and can use used with In to make its invisible to other Nen users, unless they use Gyo. The user goads the target to use Gyo then they attack with Slasher House. As a Nen contract this ability can only be used 3 times a day, or else the user loses their Nen.
2. Possession: If the Nen beast touches the shadow of the target, the target can be controlled by the user
3. Act-2: When the user snaps their right middle finger and chants “Act-2” the Nen beast transforms into a 6ft tall Nen beast that fights alongside the user with tentacles swirling around, that can be used with manipulation to attack and bind the enemy, along with the limitations of Summoning Act 2 can only be used within the area of the user’s En

Slasher House

1. Aluminium manipulation: The user can manipulate small square aluminium foil pieces (that the user carries with them in the sheath of the sword) and imbue them with Nen. The aluminium pieces can be manipulated to resemble a curved Sabre, can disconnect and reconnect according to the user’s will, change their shape and length and can be used as ranged weapons. The user can use the sword normally then suddenly disconnect some pieces to circle towards the back of the target basically bypass most defences. The user can also imbue the aluminium pieces with In to deliver an invisible slice (Think of Thousand demon daggers in scissor seven or Byakuya’s Senbonzakura from bleach)
2. The user has to carry a sword hilt, the aluminium pieces can be controlled only with the hilt of the sword as a restriction. Additionally the user must keep one hand behind their back and assume a fencing stance for this ability to be used
3. Slice n’ Dice: With each consecutive 10 hits the user conjures aluminium pieces and manipulates them to attack the target relentlessly in a 10m radius. This process continues in a cycle and more and more aluminium pieces are generated. (Think of Sukuna’s Domain)
4. Additionally if the user crushes the aluminium into powder then lights it up (with a lighter idk) then the resulting explosion and fire can be used to generate shadow for Beasts that lurk in the dark.