Movie
Description
Shunack assisted biologist Dr. Sakul in lunar genetic experiments to create trees resilient against harsh environments. His impatience caused him to overstimulate the trees' genetic code, triggering catastrophe. The mutated trees gained human-level intelligence, destroyed part of the moon, and invaded Earth, overwhelming civilization. Post-disaster, Shunack entered cryogenic hibernation with Dr. Sakul's daughter, Toola.

Awakening roughly five years before the main events, Shunack found Earth dominated by the sentient Forest. Consumed by guilt over his role in the apocalypse and rejecting the transformed world, he resolved to restore the planet. He joined the militaristic nation of Ragna, posing as an ally committed to destroying the Forest. He revealed Dr. Sakul's weapon, E.S.T.O.C. (Environmental Defragmentation System), capable of eliminating the Forest, and secured Ragna's resources to find it. To enhance his physical capabilities, he voluntarily underwent genetic modification by the Forest, gaining superhuman strength, durability, and distinctive silver hair. Colonel Jessica of the Ragna Army monitored his activities.

Discovering Toola had awakened in Neutral City, Shunack infiltrated the settlement to recruit her. Presenting himself as her father's colleague, he appealed to her desire to return to the past, concealing E.S.T.O.C.'s destructive nature and his personal motives. He destroyed a Forest creature sent to intercept them, revealing his enhanced abilities to Toola. Persuading her to join him, he escorted her to Ragna territory.

Locating E.S.T.O.C. within a mechanized volcano, Shunack betrayed the Ragna army and commandeered the weapon. He revealed his true intent to Toola: activating E.S.T.O.C. near Neutral City would reduce the area to "ashen rock" to enable ecological restoration, erasing his centuries of guilt. He disclosed his direct responsibility for the genetic disaster that created the Forest. When Toola attempted suicide to stop him, he intervened. Confronted by the enhanced Agito, Shunack engaged in a duel fueled by their shared connection to the Forest's power. Agito, embracing a full transformation, merged with the Forest and absorbed Shunack into a tree structure.

Absorbed into the Forest's consciousness, Shunack experienced a profound shift. Freed from his obsession with the past and the burden of guilt, he attained peace and relinquished his hostility. His consciousness, integrated with the Forest, expressed no further desire for conflict. This reconciliation demonstrated the potential for harmony between humanity and the Forest.