Ok why do you think Rhys is a witch?
So this goes hand in hand with the Rhys is part Valg theory. I always theorized about Rhys being part witch but when I heard this quote from Asterin on tiktok I was sure. Not 100% because not everything fits but look:
Asterin: "In the Wastes they made machines to break us apart. The fools never realized that all they needed to do to torture our kind, to make us beg, was to chain us. Keep us tied to the earth."
Rhys: "So they chained me up between two trees, beating me when they felt like it, trying to get me to tell them where the Night Court forces were, using my warriors— their deaths and pain— to break me. Only I didn’t break,” he said roughly, “and they were too dumb to know that I was an Illyrian, and all they had to do to get me to yield would have been to try to cut off my wings."
Both the tog witches and Rhys are breakable if you take away their freedom, keeping them tied to the earth. Both are meant to be in the sky
Then there is this part in acowar:
ACOWAR: Nesta drifted toward the desk, the maps atop it. “What is the difference,”she asked none of us in particular, “between a faerie and a witch?”
“Witches amass power beyond their natural reserve,” Mor answered with sudden seriousness.
(They continue to say that witches use spells and objects which Rhys obviously doesn't but except for that (also about that, Rhys's powers are used to fix the cauldron so that could be an object))
Rhys's powers: Rhysand has an extreme amount of power, that exceeds the amount of any of the seven high lords. He is the most powerful Fae in the history of Prythian,
Feyre about Rhys at the High Lords meeting: Brethren, and yet not. Tamlin was a High Lord, as powerful as any of them. Except for the one at my side. Rhys was as different from them as humans were to Fae. They forgot it, sometimes— how deep that well of power went. What manner of power Rhys bore. But as Rhysand ripped away Tamlin’s ability to speak, they remembered.
Throne of Glass Witches: Witches are a species of witch created by the mating of Valg and Fae (That's where the Rhys is part valg theory comes into play)