Its an absurd ability that can also be found on Jace, Laboratory Maniac, but we still think Thassas Oracle is better because its one mana cheaper (and it cant be destroyed in response to drawing a card)
There are several Common lands in this format that put themselves into the graveyard including the Sphere cycle and Terramorphic Expanse, so being able to play lands from your graveyard will come up some
Massacre Wurm is the kind of card that slots into a fair few archetypes, from Aristocrats to Control, and one that helps some of those decks achieve a higher level of consistency
I dont know that Nahiri ever had a strong showing when she was initially printed, but the decks that wanted her have been happy to play her
He currently avoids the rest of his family but maintains a connection to his homeworld through his association with the Reckoners, who ask about his travels and nothing about his family, just the way Nashi prefers it now