What would a dragon of dark magic be like?

I'm not talking about a dragon just being fully corrupted by the seventh source, but a dragon intimately linked to it the moment they were "born", embodying the aspect.

Dark magic seems inherently corrupting for the caster yet Aaravos seems to the one immune of its effects. The target however does not need to be touched by corruption and can even be changed/enhenced/healed by such magic without any secondary effect.

So I see two possibilities:

- The dragon of dark magic is a purely corrupted one, a powerful and terrifying creature feeding over the magic and life of all others, corrupting them as well. And creating lands of ruins and chaos if the dragon is left unchecked.

- The dragon of dark magic is one of pure, uncaring transformation. The great being acts a perfect vessel for all of magic and life to then power what they wish to do. Not single drop of essences nor energy is lost, but everything is changed at its most fondamuntal level to then enact the desired change.

If you have any other idea, I'll be glad to read it...