As its name implies, Shiny Pokmon were intended to be the focus of the set
I can see three ways to take this deck
There are tons of tokens found in Magic: The Gathering
Since the few anti-Poison tech cards are too narrow for most Commander metagames, opponents receiving their first Poison counters face an unappealing choice: either unapologetically gang up to immediately remove the proliferate deck from the game, or dont and then try to act surprised when that player inevitably wins the game a few triggers later
Overtime, however, its likely this card will drop considerably in value as double rare cards are just not quite rare enough to ensure long term value
To truly shield your permanents, you need to get them off the battlefield temporarily, whether it be via Teferis Protection, Clever Concealment, or a slow blink like Laezels Acrobatics