This skill is not learnable through a skillbook. You gotta be undead and talk to the voidwoken in the nameless isle, it's just as you enter the academy. Almira explained how the Covenant was a magical pact: those who accepted it were 'Sworn', and must serve the God King in perpetuity, even beyond death. After making it all this way, I was defeated by a fellow Godwoken, who then claimed the powers of Divinity and ascended. It's a one time opportunity, a single character can become sworn and � There are two of those present in the game: one in three pieces (plan in the Blackgates in 2nd act, blade in the Academy in 3rd act, and the haft kept by the Sallow Man, also in 3rd act), one you get near the end of the game in Arx. The critically acclaimed RPG that raised the bar, from the creators of Baldur's Gate 3. Release yourself from your oath to the God King. Voidwoken enter Rivellon through a hole in the Veil which separates the Void from Rivellon.When they enter Rivellon they bring Void with them.
Divinity: Original Sin 2 has been out for about two years now and continues to be one of the top-selling RPG strategy-adventure games on Steam. This guide to Divinity II: Ego Draconis contains a complete description of the path which awaits all those who dare to become a Dragon Knight.