Ultra cards, and one card from another universe
Meet the Ultra cards: 10 numbered Blib cards in new frames. Ultra Gold is polished metal, Ultra Diamond is cut crystal and Ultra Holofoil is a rainbow foil. Open one and tilt it (or tilt your phone) and the light moves across the frame.
Every Ultra card is a limited edition with a fixed number of copies, and the rarer the frame, the fewer there are: 100 of each gold card, 50 of each diamond card and only 25 of each holofoil card. When a card's copies are gone, they're gone for good.
And then there's Master of the Universe. Blib, floating above a galaxy, in a cosmic frame crafted in another universe: an aurora turns through its crystal, galaxies spin inside its logos, stars drift across it and sparks orbit around it. There is exactly one copy in the whole game. Whoever finds it owns the rarest thing on Blibzz.
Where to find them: the last card of any card pack can be an Ultra card. The chance is tiny: 1 in 400 Legendary packs, 1 in 2,000 Rare packs and 1 in 10,000 Common packs, and cards with more copies turn up more often, so Master of the Universe is the hardest of all. The Blibzz team will also hand a few out as special prizes.
Ultra cards can't be sold back to Blibzz. Keep them, or swap them with other players card for card. Like every Blib card, they're collectibles with no cash value.