Ink Creation

Ink Creation (インクの作成 Inku no sakusei) is the Quirk used by Shinobu and Akira
Description
Just like how blood is created in the body, the Ink Creation quirk creates ink within the user's body. When the user is born, their body has an extra organ that creates and stores ink, for their quirk, and then when the user wants to use the ink, it will flow to the skin and come out of it, and then the user can draw what they want to create, with the ink. Almost anything that is drawn by the ink will become reality, or if Shinobu or Akira wants, the ink can stay in it's ink state and be used like that. They can send it as a ranged projectile or make ink shields, but most of the time, the ink is stronger and better when draw into something. A later ability, only Shinobu learned and created as an Ultimate Move is Ink Creation: Timed Creation, in which the ink will only take form when Shinobu wants it to, or it can attached to a ally, and when in danger, form into whatever Shinobu wrote on it. 
Weaknesses
Like normal ink, when this ink is hit with water, it will slowly dissolve when hit with water, although hot water will make it dissolve quicker. Another weakness, it that if Shinobu or Akira waits too long to create something, the opponent could've closed the distance, and destroy their ink, when the ink is in it's pure state, it's quick but weak if not used correctly.