ln the past Thunder and his brother Lecter were trained in special facilities with Jerome. They retired from that facility and trained hard with their fangs in a different private facility with a new boss. Afterwards they ended up becoming assassins for Hougen. Their first mission was to kill Weed and Kyoushiro. They met Teru's father while he was complaining out loud about Kyoushiro. The two brothers worked with Teru's dad to get to Kyoushiro. They kidnapped Teru and threatened to kill him if Kyoushiro or his men were to attack. Kyoushiro threw himself on the ground on his back, offering them to attack him so he could save Teru. After they saw Weed and he introduce himself they dropped Teru and went after Weed. Thunder fought with Weed while Lecter fought Kyoushiro.

Thunder scratched Weed a few times and got tricked into biting a tree while Weed jumped out of the way. Weed scratches Thunder's nose which greatly ticks him off. He then gets hit with a branch to his mouth by Weed. When Lecter holds down Teru, Thunder goes after Weed and gets thrown to the ground by him. He tries to escape while the Ou pack is attacking Lecter. GB goes to attack his but is hit by his brother who is thrown by Hiro. He and his brother are let go, Weed asked to let them free.