I am rereading homestuck to better understand the act 7 ending, which I kind of only half understand. how did the rings bring the tadpole back? and towards the end is jade holding dirk and roxys earth? and then someone uses time travel powers to make it grow trees and stuff? and what's the thing that aradia flies in front of? how does calliope play into all this? could you maybe just explain the whole thing? (sorry :( )

The tadpole was being held by Echidna under the volcano, Kanaya had Echidna release the tadpole into the volcano and the rings made it erupt. In regards to Earth, that’s pretty much what happened. Aradia flies in front of a Black Hole that Calliope created by Collapsing the Green Sun.