I usually do class Angel and Angelus as the same, because that's what I believe. I don't believe they are seperate characters. Sometimes I spell it Angel(us). Fred/Illyria, no, they're not the same, because those are really two different entities, so I seperate those two most of the time.

I class Liam, Angelus, and Angel as the same person just different times in his life. Just like I classify William and Spike as the same, just different.

Does that make sense?

i alwasy class angel and angelus as different and well fred and illyria are different so yeah they are different! but angel and angelus were acted in complete opposite ways wheras all the other vamps were kinda the same when they had souls!

I think Angel&Angelus could be classed as the same, because they are the same person just different sides of him.
But Fred&Illyria are two different people. So i don't class them as the same.

I like to put Liam/Angelus/Angel as the same character because I see it as a progression just like William to William the Bloody and then Spike. Same person different phases of their life, like a butterfly :). Besides, it supports one of my Spuffy arguments (that being that Spike fell for Buffy sans soul but Angel went in the opposite direction. The Judge says Spike reeks of humanity but Angel is 'clean', I like making Spike good and Angel not so good).

Fred and Illyria are two different characters completely. Illyria is an entity that inhabits Fred's body, her 'shell' (ohh, see how I did that?), she is different. Fred, as we know her is dead. While vampires are demons that take over the hosts body the host is still there in a way, with Illyria it was just the hallow memories and none of the emotion. She is so far detached from emotion while Fred was such a heartfelt character.

As I write this I see that I am agreeing with Nika again, so yes, ditto.

I generally classify both Angel/Angelus and Fred/Illyria as the same people.