Kyran always thought that the reason he could combine the two was because both were his Innate magic. He remembered that every time he combined them, he would use Draconic magic as the base while Void magic complemented it.
For example, the Void Scales came to be after combining the Regis's defensive technique— which he soon learned was Draconic magic— with Void magic.
There was also the Void Needle. To ensure that they would expand without 'disintegrating' the insides of his target, before making them explode, he applied the Regis's tempering technique with the Void magic.
But now that he thought of it, using Draconic magic as the base was not really necessary. With the Void magic's nature, there was a possibility to affect the nature of any magic that made contact with it. That had always been the case with other magic.
Then again, Draconic magic was different; it was Ancient magic.
But what about Soul magic?