[And he had, really -- meeting his glowing blue friend was enough of an indication that not all magical things are bad, and Mordred... well, he was a nice enough kid, a good knight, and even with how things ended up as, Gwaine can't think he was completely evil. Not because of his magic, at least.
And if the magic here is bringing him in after he's died, giving him a chance to meet those he cares for again -- how could that be evil?]