These cards represent key locations from the FINAL FANTASY series
Some abilities trigger whenever you "expend N," which happens when you've spent N total mana on casting spells during a single turn
4 Ajani, Adversary of Tyrants For white decks based around the use of creatures, Ajani, Adversary of Tyrants is a powerful four loyalty Planeswalker for four mana, capable of flexibly synergizing with creatures in several ways
If that sounds fake to you, show me another card that generates 10 power and toughness for six mana out of the can
Gray Merchant of Asphodel Gray Merchant of Asphodel, commonly known as Gary, has been one of the best drain effects ever printed
That said, Possibility Storm was mostly unplayable from a competitive perspective because the deck-building cost was too high, until the right support mechanic (adventure sorceries) came along and made it into the centerpiece of a legitimate deck, so it might just be a matter of time until something breaks Unpredictable Cyclone as well