He is clearly identifiable by his "creepy" appearance, covered in black armor, face half concealed and constantly sticking out his tongue and laughing maniacally. Bixlow refers the dolls he controls with his magic as "babies". Bixlow seems to like souls, which fits in with his actual magic and figure eyes.
Bixlow possesses Seidhr magic, which allows him to seal wandering souls into dolls or objects and manipulate them. This is shown by the five dolls that float around him. He fights by sending these dolls flying about rapidly and having them fire beams of energy from their mouths. Because of his type of magic, he is also able to see human souls. Bixlow, like Evergreen possess a special eye magic which allows him to turn anyone who looks into his eyes into dolls, allowing him to control their souls. Aside from his magic, Bixlow is relatively weak physically.