The official website has revealed the effects of the Yuya-Yuma cross over monster!
VJMP-JP147 希望の魔術師 Kibou no Majutsushi (Hope Magician)
Rank 4 LIGHT Spellcaster Xyz Pendulum Effect Monster
Pendulum Scale: 8
(1) Once per turn, when any player’s monster declares an attack: You can negate that attack, then destroy this card.
Materials: 2 Level 4 monsters
If you can Pendulum Summon Level 4, you can Pendulum Summon this face-up card from your Extra Deck. You can only use this card name’s (1) monster effect once per turn.
(1) You can detach 1 Xyz Material from this card; Special Summon 1 Level 7 or lower Pendulum Monster from your hand in Defense Position, but its effects are negated, then you can place this face-up card in your Pendulum Zone.
(2) If this card is Pendulum Summoned: You can target 1 Pendulum Monster in your GY; attach it to this card as Xyz Material.
An Example Video from V Jump of how to use the new card: