well azdrazi when they die turn to ash
and heraldry/azdrazi are not 'dark magic' or entirely dark entities. They are draconic which are very different things. It just so happens that Azdromoth, the guy who made the azdrazi, is evil. (Ima leave out corrupted azdrazi since those things are evil)
it is like saying uhh.... bit of a bad example, but because Kha are made by a daemon and have their roots inbended in questionable origins, they are not inherently 'evil' as their soul isn;t tainted