Board Thread:General Discussion/@comment-6192846-20130929130231/@comment-6192846-20150110015305

I agree, it may be a suggestion of his personal opinion, but the facts back it up and he was very clear on everything except the actual name origin (all we can say for sure is that it intentionally references KAITO [big shocker]).

It's an informal tweet, but I didn't find any implication he wasn't considering his suggestion legitimate for canon (that was what was being asked of him in the first place).

I don't think this issue is debatable. Of all the potential options, mothy thinks "Karchess" would be the most appropriate. This suggestion is what he believes makes the most sense for an English translation.