You get the

by finding the zodiac book, and then everytime you find a statue, like

or

then the zodiac sign appears in the background of that level and stars randomly drop to be collected. After you have collected all the statues (just one of each), you will be able to start collecting potions like

and

. These do almost the same thing as the statues, but now the background doesn't change but each badguy left on the screen drops a

. I think after you've gotten all the potions (1 of each again) you are rewarded with the ability to kick bombs upward, but i'm not sure. By the way, the zodiac book is rarity 5 (really rare, highest is 6, which is like ridiculous), and the statues and potions are rarity 3, which is about as tough as finding

or

perhaps. Anyway these quests take forever, but eventually you'll find it! Good luck!