Silas

Silas is a former warlock who became the first immortal being in the world. According to him, he was responsible for creating and casting the first Immortality Spell on himself. However in Original Sin it was proven that he and Qetsiyah were responsible for creating the immortality spell, as both have claimed creating it.

Silas is the most dangerous immortal and supernatural being in the series universe (however, it is unclear whether he was more powerful than Qetsiyah as a warlock). He is the main or major villain of Seasons Four and Five.