Ink Sans is the guardian of the Au's,he is responsible not only for taking care of the Au's but also for helping to create them [but he does not create them]. This exists outside of any timeline. With his brush he can bring to life everything he draws,except that he cannot bring to life people/monsters that are already dead. This includes Au's. He drinks "vials" that are little tubes with colors to feel emotions because he is soulless.