The new jeweled beasts are definitely cards of all time. You can search masque, masque units, g4 units when youre on g3, g3 regalis pieces, any g3 swingers your deck uses, the Destined One orders, etc. They’re nice if your vanguard has some alternate form sitting in the main deck such as Avantgarda, Lianorn, or the Masque units (assuming all nations will get the same thing)
The question is would masque decks even want to run these cards? Just the sheer size of the masque engine already eats up a lot of room in the deck, do you really want to put more cards in that only exist to facilitate the masques, or do you want to put in more cards that help the decks themselves?