[Time to add 'walking encyclopedia' to the list of things an angel from outer space should not be, and yet is.

Differences in spans of time aside, it does sound like Earth and Aselia measure time in roughly the same way -- at least when it comes to telling how old someone is. It also sounds like angels are functionally immortal. There aren't many sorcerers who will take the existence of something greater than them well, and precisely none of them are worshippers of the Faceless Ones. If Kratos wants to stay on Earth for any length of time, things might get difficult.]

Humans -- we call them 'mortals', which isn't very fair of us -- live for one hundred years. Sorcerers, on the other hand, humans like me and Ghastly who can do things like this -- [Palm flame on, palm flame off.] -- we live for a thousand years too. And this...

[Skulduggery makes a gesture that takes in all of his skeleton-ness.]

I'm unique. There's no one else like me. I might live as long as angels do. Right now, though, I'm a little over four hundred. How old are you?

[There is literally no answer that will surprise Skulduggery at this point.]