Destroy this creature at the beginning of the next end step
Fuse (You may cast one or both halves of this card from your hand.) Watermark: Selesnya Illustrated by Nils Hamm Standard Not Legal Alchemy Not Legal Pioneer Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
As are Eternal Dominion, Mnemonic Deluge, and maybe ever blue spell that costs 8 or more
Presumably it will release in Japan's Shiny Treasure set at the end of the year
More common are kinds that change a type based on flavor, like converting something to a vampire with New Blood, resurrecting a hero as an angel warrior with Ascent of the Worthy, cursing the greedy to become, um, walls with Aurification, or resurrecting cards as zombies with Dread Slaver
It is more balanced with this reprint, but still massively powerful for deck acceleration