[Verginius Rufus]

He was one of the Avignon popes during the Great Western Schism. He made some attempts to end the schism by offering to abdicate if the pope in Rome would do likewise, but they fell through, and even after the Council of Constance declared him deposed and elected Martin V, he continued to call himself pope.

It would be hard to treat him as a legitimate pope at this late date--for one thing, there was a legitimate Benedict XIII later (just as the 20th-century John XXIII took the number XXIII although there had been a John XXIII during the schism).

Are Pedro de Luna's adherents called Lunatics?

[ebb tide]

Are Pedro de Luna's adherents called Lunatics?

That would be the best you could call Jorge and Tucho.

[Marchmain]

“lunatic” - Latin root moon.