how rare are first edition pokemon cards 1999 Pokémon 1st Base Set Charizard Holo Holy grail' 1990s Pokémon Charizard

It gives you whatever mana you need to cast a legendary creature, then lets you leverage the legends you have in play to fix your mana for other spells

The way to think of most modal spells is that they provide the caster with multiple spells of which they can choose one to cast (and sometimes more than oneI'll get to those in a moment)

Swarmyard Massacre: One sided board wipes are strong, and doing it for 5 mana is extra strong

There are just so many cards that work well with Birgi that you can capitalize with something as simple as Burning Prophet and Guttersnipe, or as complex as Defiler of Instinct

While we've seen similar effects before, the only one that's Modern legal is the six-mana Time Stop, which is simply too expensive to see tournament-level play