That would be amazing!! It would be great to see what the great aunt was doing before getting to her nephew's house, and tying the tree into her sickness. Or giving us what Alex does since he's truamatized now and learned how to use the tree. Maybe he keeps control of his classmates and uses them all as a villainous adult. Maybe he discovers more ways to use the tree's powers and attempts to get his parents back. Maybe he stays a hero and tries to rid himself of the tree, but the tree's health is connected to his mental wellbeing.