Insider here.

Imu was Joyboy 's twin brother.
Jealous that Nefertari Lily was in love with Joyboy and not him.
Nefertari Lily was the very first Amazonian in the One Piece world.
"Amazon Lily" is named after her because she was the one who founded the nation.
Luffy had the ability to give other people Nika powers. The first person he does this for is Usopp, who does 1000 ton hammer by pulling it out of his pocket and hitting Killingham with it.

That's all I have.

c-chapter this week? why nobody posts hints