In order for this WeakAura to work the Raid Leader will need to have the boss marker WeakAura which you can find here: https://wago.io/5q3zuvDrx
Bug:
The interrupt count will not reset for the last phase of the encounter meaning that the weakaura will display whatever number was the last cast before you phase the boss to 50%.
Example: Prototype of Renewal phased to 50% on interrupt number 6, whenever last phase starts the weak aura will display interrupt number 6
Original aura made by Causese: https://wago.io/interruptorder
Just configured it for Prototype Pantheon and Renewal
Always be checking for updates