SoutionSolution:
- Event X is here. Three years in the making, now it delivers your chance to shine at our epic event.
Problem:
Event X is here. Three years in the making, now it’s your chance to shine at our epic event.
The event is what was three years in the making. The it's following the opening phrase has the dummy subject it and does not directly refer to the event. Yet it needs to, or the reader is left hanging: "What is three years in the making? My chance is?"