Okay, so I feel like people forget that Aku is a tree.
So his daughter is also a tree, right?
So that sakura tree Jack is standing under in the last shot is Ashi.
There’s such beautiful symbolism in it, too. Aku destroyed mother nature, turned the world into a twisted and cruel place- but Ashi, in death, has become part of nature. She is exactly what Aku hated, a final defiance of the destiny her parents tried to force on her.