Freyla, Legacy of the Sylvan

Whenever a land enters the battlefield under your control, you get an experience counter.
You may play X additional lands during each of your turns, where X is half the number of experience counters you have rounded down.
{2}{g}{g},{t}: Elves you control get +X/+X until end of turn and gain trample, where X is half the number of lands you control rounded down.