User blog comment:Lady-warrior/Ferrets are Sweethearts/@comment-24479943-20140319215833/@comment-25220117-20140324233309

The Outcast of Redwall probably ended with Veil dying and Bryony acting in such a way because BJ wanted to show that even when growing up alongside good creatures, vermin can't ever turn out completely good. Even if he showed Veil's sacrifice as a way of saying that some vermin could have a little bit of good in them.

Same with Deyna in Taggerung. Even despite living with evil creatures, he never gave up on being good. It's just a way of saying that vermin will always be completely evil and goodbeasts will always be completely good, with only little exception.