graded card pokemon Pokémon Mystery Box! (PSA, CGC, BGS) GameStop Reselling Pokémon Cards In

If your opponent has 8 DON

Collector Boosters Horrify your opponents with Borderless, Double Exposure, Paranormal Frame treatments, Full-Art Manor lands, and Mirror Monster cards

If I had to hedge a bet, Id say that your opponents are more likely to let you draw cards than to discard their own

There's a few other very good proliferate engines, such as Contagion Engine, Thrummingbird, and Guildpact Informant for repeatable proliferate, and Tezzeret's Gambit, Vivisurgeon's Insight, Contentious Plan, and Steady Progress adding proliferate to card draw which is great to have

A thorough examination of the card (and Merfolk in general) can be found here