Savolla is a boss-fight in the video game The Witcher and was described as a sorcerer "as powerful as he is insane" - he was responsible for controlling a Frightener (presumably of his own making) by which to break down the defences of the Witchers' castle and allow a band of bandits to raid the area.
Savolla also made sure to keep his presence known by occasionally firing powerful bolts of magic at any who strayed too near - when he was finally confronted he showcased the ability to teleport as well as numerous other mystical powers but was ultimately to fall by the blade of the legendary Witcher.
He's a minion of Azar Javed.
The Witcher 2: Assassin of Kings
The Witcher 3: Wild Hunt