Frankenstein's Monster is a classic Castlevania boss. He is large, slow, and accompanied by his little helper, Igor, who jumps around and throws projectiles. The Monster's weak point is his head.
Strategy: Focus your attacks on Frankenstein's Monster. Igor is a nuisance but will eventually be defeated if you keep hitting the Monster. The Monster walks slowly back and forth, occasionally jumping. His main attack is a powerful punch. The Holy Water sub-weapon is incredibly effective here; throw it on the ground where the Monster will walk, and it will deal continuous damage. The Axe can also hit his head from a safe distance. If you have Sypha, her Fire spell can melt through his health bar quickly. With Grant, you can climb the walls and attack from above. With Alucard, you can use his bat form to fly over him and attack. Prioritize dodging Igor's projectiles and the Monster's punches while continuously attacking the Monster's head.