Beast Beasts are an older tribe that's rarely if ever seen on new cards
They possess a unique scouting mechanism that allows players to peek at the top cards of their deck, smoothing out future draws and ensuring players have the right answer ready
If you have more than 4 of a unique card in your collection (or more than 59 of a basic Energy, or more than 1 of an ACE SPEC, Prism Star, or a single part of a V-UNION card) when it is migrated over, those extra cards will not be carried over, which might seem bad at first but since youll only ever need 4 of a card at most for decks and since trading will no longer be an option, it isnt a major issue
As if protecting its owner from the Shaheeli Rai / Felidar Guardian combo with only one counter werent enough, it keeps other creature decks in check, and can convert a bunch of mana into an insurmountable battlefield state if left untouched
Also, in Magic Origins , we were telling the story of Lilianawho makes a deal with four demons