Mechanics like these can fundamentally change the way the game is played
This lets you dig for the halves of Brisela, or get Linvala to stop shenanigans, or get Lyra for lifelink
All that said, there's every reason to be playing this in a Dragon deck, which means there will be every incentive to drop it for two mana, swing in for one, and play a Mox JasperMox Jasper in second main
It stretches availability and makes a theme that might not have the footprint to work more viable
Illustrated by Mark Romanoski Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
When this creature leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost