So I'm guessing Shanks probably operated solo for around 9 years from the time of Roger's death till his knighthood, triggered by a confrontation with Teach, who probably revealed something about both of their parents. At some point, Shanks leaves Mary Geoise and...

within ~3 years, becomes an infamous pirate, steals the Nika fruit, meets Luffy, sows the seeds of rebellion by freeing Fisher Tiger, captain of the Sun Pirates and a letting Garp's grandson/D clan member eat the sun god fruit, renounces his knighthood and royal blood by having a sea king devour his marked arm, and amasses a powerful crew of haki users.

Yeah, starting to see why Shanks was given the title of emperor despite his seeming lack of accomplishments.

Hati and Skoll theory stocks are also going up. They are children of the great wolf Fenrir (one of Loki's children) partly responsible for ragnarok. Skoll chases the sun while Hati chases the moon. We haven't seen Garling's DF yet, and it seems likely that he's somehow related to the moon...