Music Box

The Music Box was an important object in the Super Mario series. However, it is only referenced. At some point, it did hold a lot of significance. But since then, it has been destroyed in-universe.

Creation and Fallout
The Music Box was an object created by the first lord, along with many other objects such as Peach's Brooch, Len's pendant, and more. It was originally made to trap the devil's soul, but he escaped when the arch-demon Abor set him free. Since then, similar music boxes have been created to trap other evil beings, one even containing a certain mysterious monarch and a scoundrel with a "heart for gold", for a time.

Usage Time
The Music Box was eventually given to Len when she became the newest lord, the old one resigning from his authority and disintegrating into dust. She was also gifted mountains of jewelry and precious artifacts. For many years, Len would sing along to the tune of the music box at night. But then, she found that one of her subjects, Riba, was going to marry a dangerous woman, Alice. It would be the perfect opportunity to study human nature. She saw it all lied out in front of her. This would lead to a mansion. Dangerous spirits. How long could you beat someone over the head with a bat until they truly break? It was perfect. It was fate.

So, on the day of Riba and Alice's wedding, Len gifted them the Music Box to seal their fate, if you will. They took it without a second thought. When Riba eventually killed Alice, she placed a curse on the mansion and its surrounding area to make it so nobody could ever leave unless they gathered the Witch's Artifacts. Riba was stuck inside the mansion. Anna, Riba's child, used the Music Box to seal Alice's spirit within so she couldn't spread the curse. In doing this, she also made it so she couldn't remove the curse.

This is when Mario showed up in the picture. He arrived at Aduraice Mansion many centuries later to explore the many disappearances linked to the mansion. Anna, who had now become a spiritual entity, believed him to be their savior. Somehow, she expected him to free them all of the curse. However, Mario instead inadvertently broke the seal on the Music Box, releasing Alice's spirit back into the world. Mario took the Music Box with him, commenting on how beautiful it was. Instead of immediately spreading the curse, Alice soon possessed Mario in order to feel alive again.

Mario, possessed by Alice, continued on his journey through the Aduraice Mansion and Evangeline with the Music Box. When Mario defeated Marchionne, his pre-iteration, the music box broke on its own. Perhaps it will make a comeback some day. After all, old relics die hard.