Hmm, the last time we made a spelling correction on one of the character's names, it was with An Yu, because we all thought her name was spelt like this - Anyu (according to how it was spelt in one of her toys) - before the episode title card revealed the actual spelling.
I'm thinking that it might be the same for Mothzuki, but I'm not sure. It could possibly be a spelling error in the source where the episode was found.
However, I do agree that we should leave the name as it is before making any changes. Just for right now, though, until there is a clear confirmation of how Mothzuki's name is spelt, because as I said before, it could either be a different spelling than we thought, or a spelling error in the source.