I would rather assume all of us qualify as 'mortal' than not.

It may only be how they themselves interpret good and evil. [Whoever they are. He's got a guess about that, though.]

I wonder... The beasts that were brought before the mirror were deemed 'unworthy', but it is never stated what happened to them after. Perhaps this is an anecdote of the beasts, from Lilith's question for perfection.

[Everyone's unworthy according to their standards, after all. Childermass' piece mentioned their complete failure for success of getting one side without the other.]