Yawgmoth's Testament [Mystery Booster: Convention Edition Exclusives] Fusion Monster and Mox Amber is one

and Mox Amber is one of the better ones

Number: MRD-000 Rarity: Secret Rare Attribute Monster Type/Card Type: DARK Warrior/Effect Monster Level: 11 A / D: 3750 / 3400 Description: This card can only be Special Summoned by offering Sanga of the Thunder

Attack 1: [L] Thundershock (10)

Attack 2: [L][#] Thunderpunch (30+)

You may return all Energy cards attached to Dialga to your hand

Yawgmoth's Testament [Mystery Booster: Convention Edition Exclusives] Fusion Monster and Mox Amber is oneRarity: S Card Type: Sorcery Description: Until end of turn, you may play face up cards you own from exile. If a card would be put into your graveyard or exile from anywhere this turn, put it on the bottom of your library instead. Flavor: TEST CARD Not for constructed play.