Replacing its other types! Potent.

I think I'd give this the colourless land background, because of how effective a hoser this is on opponents' funnylands.

That's probably a good idea.

Yeah; this is almost a Stripmine you don't have to sacrifice to use. Very potent. (I mean, it isn't, because most decks can use at least some some off-colour mana; but I would probably run 4 of it in every deck).

Vitenka, your comment made me realize I forgot "nonbasic."

Ah, now it's a one-shot instead of repeatable, and only hits funnylands? Good call. I'd still run it.

Hm. Now its got an odd problem that you may not play out your lands because you don't know if your opponent has a nonbasic coming up. Though, I got to be honest that that problem probably isn't worth trying to fix.

Yeah, it's skill testing now. It's also slightly flavour-weird that you can cancel out one meteor with another. (It's still got a counter, but the coutner no longer does anything.)

No, once this turns something into a mountain, nothing you do to this will stop it from being a mountain. See Obsidian Fireheart

I'm not sure what Vitenka and jmgariepy think this said before, but the only change is that the effect is now tied to the counter being present. It previously said "When ~ ETBs, put a fissure counter on another target nonbasic land. That land becomes a Mountain."

I think they were parsing it as two abilities, like That Which Was Taken

does this allow two or more to be on it and still work? it shouldnt happen because no player would do the same thign again on the same land, but proliferate shouldnt break it imo

Gaining an additional counter wouldn't affect it.