[spoiler=Alpha Ethereal Sphere] Lore: 2 Level 4 LIGHT Machine-type monsters Once per turn, you can detach 1 Xyz Material from this card: Equip 1 monster from your opponent's Graveyard to this card as an Equip Spell Card
Sadly, for players hoping to to go hunting for some serialized Bobbleheads, Collector Boosters look particularly difficult to hunt down thanks to supply issues
The turn this card is summoned, it gives you the option to attack twice
It offers you a way to discard a card without paying mana, which lets you use it with Hashaton's effect to easily make Zombie tokens of your expensive creatures while getting you a card in your hand to replace it
For each of those slots, youve got about a 15% chance to hit a mythic
So another way of thinking of them is that they can be Advantage Dangers, but only in certain situations