The last tree

Neat, but I think the colorizarion is a bit too green. Not sickly green IMO, which probably is the way you headed, but maybe a bit too lush. I think more grayer brownish green tones would give more industroius disease effect.

for me it works as it is - a little dreamy and ?innocent?.

what you suggested would take a bit different approach and modelling, I guess - to deliver the (same) message. More repulsive and cold, maybe more in the *666 vibe as drawn on the first ship’s hull. More Autodesk if so to speak …