4. Increase his mass media appeal
In this day and age, it's not enough to simply be a good, or even a great, wrestler. You have to worry about your platform on social media, and how many people outside of the wrestling business know your name.
For example, Hulk Hogan and the Rock are famous both inside and outside the ring. This is due to movie roles, their appearances on multiple forms of media, and their influence in the sport and beyond. Even Ric Flair, who spent most of his time wrestling, has appeared on shows like Thunder in Paradise and was the subject of an ESPN documentary which earned critical acclaim.
If Omega wants to be the GOAT in wrestling, he'll have to do similar things. However, he seems to realize this and has said he wants to do acting and other forms of entertainment as well as wrestling.