Wergh. Interesting. Normally an advantage, like Elvish Pioneer, but requiring a basic Forest will have deckbuilding implications too.

I liked the idea of turning a bonus into an outright cost. Maybe basic land would be slightly less harsh, but then the mana cost wants you to use forests anyway.

One problem with this: Will people know you can cast this on turn 3 by putting the Forest onto the battlefield and then tapping it?

Don't you have to pay all costs at the same time?

Well, that sort of stuff is why it's a rare :p

I like that this new version is both better and worse than Farhaven Elf/Borderland Ranger. Maybe I should had some extra keyword, though? Thinking Vigilance or maybe Trample.

Maybe this creature can be bigger? All I know is that if you didn't include the sacrifice line, I wouldn't have batted an eye. That infers to me that you can get away with a 4/3, or possibly even a 4/4 here. I mean, it sounds broken... until you get to round 3 in a game and don't have a Forest in hand...

Well, it's a curious combination of benefit and drawback. It's rather hard to balance, and would likely need actual playtesting from development rather than the theorycrafting which is all that all of us can do.

Meh. I don't think it's much of a theory. Without the sacrifice, this would be a fair rare. It would probably be an acceptable common.