Flotsam / Jetsam The second half of Flotsam / Jetsam acts like a budget Breach the Multiverse, though it misses out on your own graveyard
The deck features a number of efficiently costed rat creatures that cause your opponents to discard, quickly taxing their resources including Burglar Rats and Nezumi Bone-Reader
Prosper, from the accompanying Commander decks, is an interesting case, because it is the first time they tried to find synergies for the mechanic
You can entirely base a deck around it or just throw it into a deck with sufficient creatures and it will perform very well
Cards similar to Blight Mamba include Plague Myr, Lost Leonin, Glistener Elf
White is all about controlling the board with mass removal, and theres nothing worse than losing the investment of creatures on your own side of the field, especially with Whites struggles with rebuilding in the mid to late game