As far as Yawgmoth is concerned, you, your opponents, and planeswalkers aren't Humans
Destroy target permanent is an effect that can be used to destroy any permanent, including lands
Arwen marks a turning point for our sandwich section because, while the mechanics on the card are super satisfying (they represent her eschewing immortality to live a mortal life with the one she loves, and how that choice imbues them with strength and determination) its also let down by the fact that every other Elf in the set isnt indestructible
Sacrificing creatures lets you scry 2, giving you excellent top deck control, and then you can exile the top card of your deck to cast itdealing damage equal to its mana value to anything
Atraxa is too low impact here, especially without a red pip, giving 1 energy a turn while making you a target by playing the most popular and powerful commander in the game