Interesting. I wonder if you want to keep this to just nonlands. Because, as it stands, this can effectively cost , or any other CDEF. And you can just use a single Harrow to get there.

Not that that doesn't require some deck-building and dedication. I just figure that this might be too simple a trick to pull off in two color decks that splashes for a third color and includes a selection of different, but roughly equivalent nonbasics. Which might cut into what seems like what this card's theme is supposed to be: Play with as many different named permanent spells as you can. If you can get enough different nonbasics, though, you shouldn't need to bother. Just play two different named permanents, have four different named lands, and drop two of these on round four. 12 to the head.

Snow lands Intensifies

I dunno; I think this works as a way to encourage rainbow decks. Though it also works well late game in a mono deck too.

One problem with the "cost less for each" as a mechanic is that it only works on big stuff; rather than also while in play. You really only want it on ETB stuff though, because ugh, recounting this every time.

This was intended to count lands as well, jmgariepy. No comment on the balance, though. 😅