Steven Universe: Unleash the Light

Connie and Lion are located in the Rainbow Palace.  You will need a total of six rainbow keys to access the room where you can recruit them.  They should come with the Lion Charge ability already unlocked by the time you recruit them, but just in case: they were at level 7 when I recruited them, and they had the ability, so if you've recruited them at a lower level, you may need to level them up first.

This is pretty easily done in the same area where you did It's A Wash (Alien Moon 1-8) or where you did Clod Goals (Demantoid's World 2-8).