|Magus (Fiendlord's Keep)|
|Crono, Frog, and Marle face off against Magus in Fiendlord's Keep|
Magus is one of only a handful of bosses you fight more than once in Chrono Trigger outside of Lavos. Like most other repeat bosses, the first battle is mandatory, but the second can be skipped entirely. Unlike the other repeatable bosses, however, Magus will join you as a playable character until the end of the game if you choose to skip the North Cape encounter.