Purphoros allows for each goblin to provide extra value in the form of direct damage to one's opponents, causing each opponent to lose two life whenever a creature enters the battlefield under Purphoros' owner's control
Unfortunately, the tins do not contain the Pokmon that features on their front (well, the boosters might if you're very lucky, but then so could any other pack)
"Meet the Winners of the 2024 Pokmon World Championships"
I dont remember exactly how the game ended, but I do remember many turns went by with three of us not casting anything because the creatures we drew would just get eaten by Fleshbag Marauder
Since the Dragons mode only cares about creatures leaving the battlefield instead of dying, some sneaky flicker and ninjitsu tactics can make Outpost Siege better than average
Apparently, the folks at the Pokemon Company suffer from this too