Empress's Minions drop Lv.140 equips.

It constantly dropping from a hacked source and a half or less drop from a once solo-able boss vs chance to get it from literally anywhere? All the books have an equal chance of spitting stuff out afaik.

It'll obviously deflate. ._.

Deflation seems unlikely from the way spadow described the change:

But after that patch, it changed to boss monsters and regular monsters.

I’ve seen screenshots of people getting Maple Warrior 30 and Sharp Eyes 20 from it and they cost a lot in my server.
Be prepared because this change will most likely happen in your version sooner or later.

The next day, Nexon announced a minor patch and in that minor patch they removed the notices of the Treasure Monster drops and they nerfed the spawn.

Now I barely see any Treasure Monsters after the minor patch.
Thanks to Nexon I cannot get my Maple Warrior 30 book! >_<

- Mastery books are already a rare drop from regular mobs and treasure monsters had their spawn rate nerfed.

- Boss monsters now have random/secret mastery books.

With those two points in mind, I think it would be safer trying to get the needed books now rather than wait
to see how things go with chaos.