Magus

Magus is a character from Chrono Trigger. At first hinted to be the main villain, he ultimately becomes a WALKING SPOILER. While some details about Magus' role in the original game were spoiled in Boo's Pizza (such as the whole Prophet business and the whole Janus business), my advice is to just play the game before diving into anything else.

Magus made appearances in Boo's Pizza because AwdryFan is a huge Chrono Trigger fanatic. There's a lot that he was planned to do, but ultimately he ended up just working in the background because AwdryFan was a) too secretive b) afraid he'd ruin Magus' personality c) afraid of spoiling Chrono Trigger because deep down he just wants everyone to play it d) the RP died before AwdryFan could really do anything. In the RP, he did stuff like get ShyHo arrested for terrorism and war crimes. At the very end of BP1, he dueled with Sephiroth and eventually disappeared into the Lifestream, which has since been confirmed to have been inhabiting another Lavos. He did stuff on day one of Boo's Pizza II as well, however he'd eventually be retconned with the other Square characters.

Boo's Pizza II
After the de-Condemnation, Magus was deported to 12000 BC. During the invasion of the Nightmare Fleet, Take called Magus in an attempt to enlist his assistance. However, as it turns out, Magus ditched the Epoch in Ioka Village and froze himself to return to his own time. Take is understandably livid that he did this, let alone steal the Epoch in the first place. In order to get him to retrieve the Epoch, Take lies and claims that ShyHo, Lavos, and Queen Zeal are responsible for the Nightmare Fleet.