And to this topic - all things about Alvin are quite silly. Devs maybe just wanted to set game closer to books. But they did that wrong way - they put that very easy, just collected best abilities and great power and put that into strange boy. I don't know why they did that - whole witcher saga was about Geralt and Ciri - very (maybe most) important person, which could change everything, which was hunted by everyone and which slowly learned about her very rare powers.
Now we got small boy, nobody really cares about him, he can teleport himself quite easily, he can read minds and break dwimmerit block. Seems like one Superman character between quite normal people. And that unclear thing about his future ...
I count with him like with little mistake. Inspiration is obvious, but he is not comparable to Ciri.
I think he is really not son of Ciri - there is no reason to for thinking of that.
Unicorns represents the highest level of magic power (for me). We don't know everything about Ciri's powers, but I expect she is more powerful than Aen Elle - that is reason, why they want her - they can't travel wherever they want. And I think (but that is just my opinion) unicorns are more powerful then her.