For almost 25 years, Yu-Gi-Oh
The conditions are that you need a chunky creature and that youre hitting a smaller one, but thats not hard for Gruul particularly with so many cheap and pivotal creatures being deployed to curve out
The value of X is calculated only once, as Consult the Star Charts resolves
The earth suddenly trembles, and the monstrous Supreme Sovereign Serpent of Golgonda, appears
In North America you'll be able to find these anywhere you normally buy cereal, but internationally it is going to be much more difficult
If you control just one Harness the Storm, you only have one chance to cast a graveyard-based, similarly-named card, no matter how many copies are in your graveyard