>>32098127That's like asking if a human is a waifu. It depends on their personality, and with Mismagius you can only project your ideal personality or make inferences from its design.
Basically, you can say a Mismagius is a waifu in the same way you can say anything is a waifu. When you're basing it solely on its appearance, though, it's a meaningless term. You can say Mismagius is cute, or well-designed, or you want to fuck it, but calling it a waifu is stupid.