There are only a few rules of superhero sequels. Number one on the list: More superheroes than the last movie. The only surefire way to outdo a blockbuster people liked is to give them basically the same thing, only bigger, bigger, bigger.

So it isn’t surprising in the slightest to read the new report over at that Marvel and writer/director James Gunn plan to expand the ranks of the Guardians of the Galaxy when they return for their mega-sequel (named Guardians of the Galaxy Vol. 2 at the moment) in the summer of 2017. They put the total of new Guardians in the film at three:

According to a source close with the production, Peter Quill will be signing some new members onto the roster; he’ll be joined by Yondu, bad girl Nebula, and newcomer Mantis.

Yondu (played by the great Michael Rooker) is a no-brainer; he was one of the standout supporting players in the first Guardians, and Gunn loves working with Rooker (he also appeared in his great horror comedy Slither). Nebula (Karen Gillan) would be an odder fit, mostly because she spent Guardians 1 trying to destroy the team (and particularly her sister Gamora). Mantis is a character with a long but not particularly distinguished career in comics. She was a member of the Avengers for a little while in the 1970s, and spent a lot of time hanging out with a hero named the Swordsman (he, uh, he uses a sword). The whole Avengers connection with Mantis could be interesting, if only because it gives the MCU another character who could bridge those two franchises down the line. (Just a few days ago, reported that Guardians 2 will also feature Ego, the Living Planet (who, uh, is a living planet), which would up the weirdness factor of this sequel significantly.)

Star-Lord, Rocket, Groot, Gamora, and Drax will be back — with or without any new members— Guardians of the Galaxy Vol. 2 opens on May 5, 2017.