How do you complete the quest Supersonic Punch on Castlevania Portrait of Ruin?

To complete the "Supersonic Punch" quest in Castlevania: Portrait of Ruin, you need to find and defeat the boss called the "Skeletal Soldier" in the "The Ruins" area. After defeating the boss, you must collect the item it drops, known as the "Large Heart." Once you have the item, return to the quest giver to receive your reward. Make sure to check your inventory to confirm you have the item before returning.