Cards similar to Blight Mamba include Plague Myr, Lost Leonin, Glistener Elf
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
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
The key cards for this strategy are: Lathril, Skemfar Shadowsage and Shaman of the Pack for life-drain effects