Unless you have an "Astral" card in your other Pendulum Zone, you cannot Pendulum Summon. You cannot Pendulum Summon monsters, except "Astral" monsters. These effects cannot be negated. Once per turn, if you have no cards in your other Pendulum Zone, you can select 1 "Astral" card face-up on your Extra Deck and place it in that Pendulum Zone.
3 Level 10 monsters You can also Xyz Summon this card by using a "Number 99: Utopic Dragon" you control as the Xyz Material. (Xyz Materials attached to that monster also become the Xyz Materials of this card.) If you can Pendulum Summon Level 10, you can Pendulum Summon this face-up card in your Extra Deck. If this card is Pendulum Summoned, place 2 Xyz Counters on it. During either player's turn, when a monster effect is activated that targets this face-up card: You can detach 1 Xyz Material from this card; negate the activation, and if you do, destroy that card. If this card in the Monster Card Zone is destroyed by battle or card effects, you can destroy as many cards in your Pendulum Zones as possible, then place this card in your Pendulum Zone.