For Zack, you are wrong !! You can still battle him in his Bakery....
Yes, but there are two entries for Zack, "Zack" and "Guard" and if you battle Zack in the bakery that finishes the Zack entry in the Dicktionary, not the separate entry for Guard.
I hadn't even noticed that Zack had a box of his own in Dicktionary. I had discovered everything during the first meeting with the guard... Sorry =/
