That is really is so very, very perfect. It definitely deserves a proper crossover. Although, you know, the real problem with writing it is that I don't think I can come up with any details that do that series of events justice. Because they would need to be as good as that summary and my mind just boggles.

How did he trap them? What torture did he use? How did he seduce Darla and Drusilla? What was the intended revenge and how did it fail miserably?

They all need equally fabulous answers.

Do you have any ideas?

Hmm...

Although one idea is that The Immortal isn't Methos, it's Darius. He goes as The Immortal when he's switching identifies and getting re-ordained as a priest which is why he's in Rome. So the seduction could have been a hoax and everyone in on it just enjoyed teasing Angelus and Spike with it so much that no one let them in on the punch line. The torture could either involve holy items or very peculiar tea, Darius being both very ruthless and very peculiar himself. And the revenge failed hilariously because it was designed for someone living the high life and the vamps failed to notice that The Immortal was consulting with the Vatican, not terrorizing it.