red mill cards mtg Stormsplitter Made this self-mill deck to

It's effect is on-going, and you can build around it with artifact creatures or things you can't target (like Protection from Black) or indestructible stuff that can't be destroyed at all

Second, the card wasn't just good, it was very good, like best deck in Standard good alongside Wilderness Reclamation to generate the extra mana to cast it

But creature tokens are how it truly shines

A board full of elves gets taller as it gets wider, meaning that the power and toughness of many elves grow larger as you accumulate more creatures

Add in the ability to keep your best creature and the flexibility to serve as a protective spell and you have a winner