When you cast your second spell each turn, copy it (non-legendary), allowing targeted gameplay advantages
Of course, this instant can already win a long game out of nowhere, even when your opponents aren't trying to go off with infinite tokens of their own
You can play a bunch of expendable fodder to chip in with and then recur with Starfield of NyxStarfield of Nyx or Go-Shintai of Life's OriginGo-Shintai of Life's Origin in a dedicated Shrine deck with Sanctum of AllSanctum of All, too
Lathril is a wincon on its own, and adding in cards like Shaman of the Pack, Skemfar Shadowsage, and Pact of the Serpent gives Lathril EDH decks a lot of options besides simply turning a ball of elves sideways and smashing face
While the latter might not be a legendary creature, it does make curving out with spells harder on our opponent and directly benefits from the small buff that Flowering gives non-legendary creatures
Wizards had come up with exile, then return effects (a.k.a