Dual Blade revamp on RED

I don't get your question but It works like this: Use Mysty book-> Get MW30 (for example)-> Change with Maple Admin for the new level 20/30 book (they are universal, so everyone uses the same)-> Double click the book and chose which skill to "rank up". So, it doesn't matter which book you get from the Mystery book, you always get a useful Mastery book for any of your characters if you trade them with Maple Admin. I don't know if this works for Zero.

Ok guys one thing.
In KMS the ability to trade in the old mastery books for the new ones that can level up any skill was removed pretty quickly, think about it like there are tons of useless mastery books and we know we have stocks of them in our mules, and to have the ability to trade them in for the new ones for free would make the new system pretty much useless for quite a while.
Source: Plays KMS regularly especially during RED

 Spoiler

and about Zero they just simply have the books in their mirror world store both costing 5 mirror world coins each. "These coins are very easy to get by hunting and quests"