The Big Bad of Book 7 of the series (Castle Death), Lord Zahda, is initally portrayed as a charismatic Evil Overlord and arrogantly taunts Lone Wolf when he has him flung into the Maze. While Zahda isn't seen again for some time, his next appearance makes it clear that Lone Wolf's victories in the Maze and his subsequent escape have unhinged him. Zahda goes from a feared sorcerer that even the Elder Magi could only seal away to a crazed old man savagely attacking Lone Wolf.
Lord Zahda:You will die... die... DIE!!
Archdruid Cadak from the Grandmaster series suffers a protracted one. Lone Wolf's victory over the Exterminatus in Book 14 leaves Cadak gaping like a fish with his confidence shattered. In the next book he takes Lone Wolf's victory over his new monster with even less grace — he gives off a Big "NO!" and a This Cannot Be! and spends precious seconds staring at his dead monster in shocked disbelief while Lone Wolf escapes. During his final encounter with Lone Wolf, Cadak's composure is shaken again when Lone Wolf completely derails another evil scheme. By this point his death at Lone Wolf's hands is arguably a Mercy Kill.
The Big Bad of Book 1 Le Carillon de la Mort of the Les Messagers du Temps series, Gouttard de Malgrāce, is maybe an insane villain but is composed enough to first keep the Prince/Princess alive, offer him/her a last meal before letting him/her take on the trial of the tower of the Chimes of Death. If a success where the Chimes are destroyed, Gouttard will agressively attack the Prince/Princess and fight him/her in personal combat.