Each of these cards are readily accessible via third-party reselling sites, and each card's non-holographic version resells for around $2-5, while each holographic card goes for around $6-10
some of these, to my knowledge, need some minor rewording to be a bit less clunky to read but other than that i'm really into the different effects and gimmicks, if you wanted to dip your toes into alchemy a bit I'd suggest a platinum as a potential boss monster (since you already used silver, the metal of the moon), either as a fusion of gold and silver (the alchemical symbol for platinum is literally just the gold and silver symbols next to each other because it was believed to be a composite of the two) or a rank 3/4 Xyz, possibly one with a sort of reverse gemini effect that makes it a normal monster when it runs out of materials, maybe a level 1/2 "moonfang ore pup" that can SS one of the others either on death or by self sacing
When Genex Undine is normal summoned, players can send a Water attribute monster to the GY , which sets up follow-up combos with amazing GY effects later in the game
The cards themselves are available from WotC directly, and some of them include codes for Arena versions of the same cards
It's quite beautiful actually, how you can get your favorite cards from childhood for very cheap
Announced at MagicCon Amsterdam on July 17, and debuting at GenCon in Indiana later this month, Mystery Booster Commander puts a fresh spin on the concept by focusing on, you guessed it, Commander