and with his death comes the end of the Titan power overall (saving all of those who were forcibly transformed in the penultimate chapter). After all of this, Mikasa takes Eren's head and buries him under the tree that they loved. ...
which Armin recovers in Chapter #139 afterEren dies. Eren's death and Ymir's liberation by Mikasa also results in every Titan body turning to dust, and those that had been transformed restored back to human form.