And the Xyz Summoned Skull finally is constructed from the Overlay Network
18SP-JP401 Daemon no Chouetsu / Exceeds Skull Archfiend
Rank 6 DARK Fiend Xyz Effect Monster
Materials: 2 Level 6 monsters
(1): This card’s name becomes “Summoned Skull” while on the field.
(2): If a “Summoned Skull” you control would be destroyed by battle or card effect, you can detach 1 material from this card instead.
(3): If this Xyz Summoned card you control is sent to the GY by an opponent’s card: You can Special Summon 1 “Summoned Skull” from your hand, Deck, or GY.
It comes as one of the cards you can pull from the Special Pack 20th Anniversary Edition’s 4th Volume. Further news on that will be revealed as soon as possible.