The first ability says only one land can enter each turn, so the triggered ability will never happen. Is this all supposed to be one big ability? I'd get rid of the first sentence then, and say "If a nontoken land would enter the battlefield under an opponent's control except the first one they play during their turn, instead exile it and you put a Forest land token onto the battlefield tapped." a la Notion Thief. I also was to point out that land tokens seem like a terrible idea, since most people use dice and it's impossible to tell if they're tapped. I also don't see this doing anything for you, since people just won't play ramp if this is out.
upped cmc from 1 to 3
upped cmc from 4 to 5
The first ability says only one land can enter each turn, so the triggered ability will never happen. Is this all supposed to be one big ability? I'd get rid of the first sentence then, and say "If a nontoken land would enter the battlefield under an opponent's control except the first one they play during their turn, instead exile it and you put a Forest land token onto the battlefield tapped." a la Notion Thief. I also was to point out that land tokens seem like a terrible idea, since most people use dice and it's impossible to tell if they're tapped. I also don't see this doing anything for you, since people just won't play ramp if this is out.