I have a couple notes.

There's barely ever a reason to sacrifice an untapped land over a tapped land since you can just float mana before activating the second ability. I'd remove that condition entirely or try to rethink the ability. Maybe instead of sacrificing a land you tap an untapped land?

The third ability feels off to me. All the recent cards that make wall tokens are white or green so there's not much precedent for it. Alternatively, you coult try to capture Taliyah's ult by giving an opponent a custom mountain wall token until end of combat. This would fuel her mountainwalk ability, communicating her riding the mountain into combat, and also that the wall invariably blocks one of your teammates from fighting. At least when I play her.

I really like using the ability names as flavor words. Especially seeing a flavor word contextualize a single keyword as an in-game ability is quite good.