Magic Brush Kid: The Painting Warrior

Sebastian wants his mother back. He is the Painting Immortal's disciple, and he comes down from the mountain to look for her after years apart. When he finds Seraphina she takes him for a small beggar and gives him a place in her home without knowing who he is. That annoys him enough that he says nothing about it. Then Seraphina's second uncle moves to take the Shen family's ancestral house. Sebastian steps in. He can bring paintings to life, and he uses the painting the family keeps to guard the house in a contest of painting and wits against the uncle. In the course of it mother and son come to recognize each other, and Sebastian's identity comes out.