To sell these cards, Nintendo made a brilliant move: they partnered with the governments Japan Tobacco and Salt Public Corporation (specifically the Monopoly Bureau)
While its still early, several Paradox Pokmon from Ancient Roar have been revealed as part of the set list, including the likes of Scream Tail, Slither Wing, and Roaring Moon exwhich are also on the packs cover art
If a player is able to fill their graveyard through either self-mill or discarding effects, this can potentially be used to subvert the high mana costs of impactful creatures
It serves as solid interaction when it enters, forces each opponent in a multiplayer format to discard a card with chapter II, then transforms into a big flier that generates card advantage when it attacks
If there's a cost associated with having it attack, you're not forced to pay that cost, so it doesn't have to attack in that case either
Some are just somewhat-relevant pieces that fit the flavor of the deck, but not its mechanics