Casting a spell for 6 mana and getting a bonus 4- or 5-mana spell is awesome, but it means that you cant use as many cheap cards in your deck, lest you cascade from an 8-mana spell to a 1-mana spell
Dion, Bahamut's Dominant is one of the main characters in Final Fantasy XVI, and one of the many named Final Fantasy characters given a card in Magic: The Gathering's Final Fantasy crossover set
You don't have to hit an infinite mana combo to enjoy playing this card next to cards like Arbor Elf, Wild Growth, and Utopia Sprawl for lots of extra mana
You can run Primal Vigor for $25 instead, along with Branching Evolution for $20, which basically creates the same effect for your deck at about half the price
In Legacy, Death and Taxes decks running Yorion, Sky Nomad as a Companion may have enough room to run this card too
First of all, it costs four mana and in order to justify four mana, you'll need to trigger this ability three times, creating 3 power in the air