During your Main Phase: You can add 1 "Zefra" Pendulum Monster from your Deck to your Extra Deck face-up, and if you do, this card's Pendulum Scale becomes the same as that Pendulum Monster's, until the end of this turn. You can only use this effect of "Zefratorah Grammaton" once per turn.
Cannot be Normal Summoned/Set. Must be Special Summoned (face-up from your Extra Deck) by Tributing all monsters you control, including at least 3 "Zefra" monsters, and cannot be Special Summoned by other ways. After this card is Special Summoned to your field, you can Pendulum Summon "Zefra" monsters (and no other cards at the same time) during your Main Phase this turn, in addition to your normal Pendulum Summon. (You can only gain this effect once per turn.) Once per turn: You can Tribute 1 monster; Special Summon 1 "Zefra" monster from your Deck.