Especially since Phyresis Outbreak gives each opponent a Poison Counter to start with
And hey, why not both (except for the fact that Heirloom Blade will keep that one-toughness creature from dying)
However, as is the generally the case with Pokmon Search Supporter cards, because the player going first cannot play a Supporter card, its likely that Item-based search options will be preferable to this card and other cards like it
Thanks to its lack of a resource system, every hand you draw from your deck should theoretically be somewhat playable
Speed comes from consistency in the first three turns, so having a high volume of these creatures provides the damage these decks want
The card is a bit clunkily worded, but in essence, it basically splits each player's creatures into two sides of the battlefield (or the "river")