Lost in Random

Story related and impossible to miss.

At the end of the fourth city, Fourburg, you get this Achievement.

You have to Battle the Bag Brothers.

The easiest way IMHO to finish them off is with these cards:

Lucky Draw/Superb Draw
Bomb!/Triplet Bombs
Hammer of Two
Time Trap
Dice Wielder's Boon
and
Health Elixir/Super Elixir

Technically any combination works on them and the fight is extremely easy. Just use the cards that fit the best for you.

If you miss out on cards you can easily grind out the remaining cards from Mannie Dex here in Fourburg. Just break all vases. There are around 50-70 vases in this city and they are all extremely easy to spot. After breaking the vases buy ONE card from Mannie Dex, most of the cards cost around 100-200, this saves the game, load up the game, rinse and repeat, up to the point you bought all the cards from Mannie Dex.