Halloween

Halloween is the leader of the Soul Seekers, and chief wielder of the only known Canine Force, Instinct. He commonly opposes Robin's Warriors, wanting to take the powers of the Feline Forces for himself.

Origins
Halloween was a cat in the past, but was turned into a wolf in an escape attempt. This attempt was after he and Roxy had been kidnapped.

Not much is known about the cursing itself, as Halloween refuses to mention it, and Roxy's memories of it were mostly erased.

However, the curse also drove Halloween to the brink of sanity. When Roxy tried to cure him, she instead infused him with Instinct Force by accident. This did bring back his sanity, but it also filled him with rage, and he fled to the Void.

Since then, he has gathered the support of the misunderstood and mentally ill, enticing them to join the Soul Seekers and fight against Robin and his warriors.