Kel'Thuzad (alternate universe)

In the alternate timeline where Thrall died as an infant, Kel'Thuzad became the chief advisor to King Aedelas Blackmoore of Lordaeron. Antonidas and his Kirin Tor severed all ties with him.

Though he did not take up necromancy, he still gained power - in this case, political. Without Kel'Thuzad leading the Cult of the Damned, the Scourge never grew in to be a threat.