Galahad got one during a collab with the game dev of infinite stars! She posted the announcement on both tumblr and patreon.
https://www.tumblr.com/llamagirl28/719283327167873024/merlin-brings-you-an-excit...- the galahad portraits are at the very end of the post.
As for other characters, there aren't any portraits out yet, but if you scroll back far enough on the tumblr- say to 2022- you'll be able to find the picrews she did of the cast!
Edit: Also if you head over to the pinterest boards as mjmjh said, you get a really good feel as to the overall aesthetics of each character in game!