As the match report from the time notes, just the presence of the card being summoned left many to assume the game was over, the fear this card instilling in all who played through this influential period of the game became apparent
In addition, it can be evolved without problems even if it is an Pokmon ex thanks to its Veevee volve Ability
They particularly pair well with Final Fantasys Yshtola Rhul, who not only has a blink effect but also repeats the end step entirely, giving another instance of Don & Leos own blink
You can only use each effect of "Detonation Code" once per turn.
In Magic: The Gathering, an early-round mana boost can be game-changing, and Mana Vault is one of the most cost-effective ways to achieve this, especially if it's played alongside cards with an untap effect
I wouldn't jam it in a hodge-podge mixed Voltron deck because of that high cost though - but in my opinion that's what makes a well designed card for an archetype