Its a neat idea, and one Im curious to see players build around
While both Secret Rares are beautiful, there's another Lugia card on this list that tops them both
Mechanics that care about cards going to the graveyard or leaving the battlefield are optimal for aristocrats decks
That is, they're presented as cards all their own rather than using the Godzilla cards method of having the Godzilla card be essentially an alternate skin, as shown below here: This was a sweet and elegant solution that could have easily been applied here - even if they were to cards that didn't already exist
In Magic's lingo, they replace themselves
According to the rules the process of casting creature cards (or any other non-land cards) consists of the following stages: you put a creature card on the stack, define its total casting cost and it locks in, then you get a chance to activate mana abilities (but only if the total cost requires mana), and, finally, you pay the cost