Sound Stage
To Save Yugioh, Lillian decided to... be an idol!
[Concept]
Sound Stage is a new kind of Spell card that's mostly used by Lillian, The Idol Singer in my original work YGO Sixteen. They represent Background Music.
A Sound Stage is Rainbow Colored and is activated in your Field Spell Zone. However, it's not officially a Field Spell Card, thus won't be affected by any interactions that deals with one.
All Sound Stages has a special property called "Contract Turns" which is represented by a note symbol, longer songs will have more contract turns but none may be over 8.
Once a Sound Stage is activated, it cannot be destroyed or replaced in any way, unless by its own ruling effect. A Sound Stage will automatically be sent to the GY on the nth End Phase after it's activated, with N being the number of "Contract Turns" listed on the card.
Other then the above quirks, it basically behaves as a Field Spell Card
You can view an example and download the template here: https://amarillonmc.deviantart.com/art/Yugioh-Custom-Mechanic-Sound-Stage-678430122
Examples
(https://i.imgur.com/U5ORI0C.jpg)
(https://i.imgur.com/W7lHMKE.png)