Slayers (1995) : 1x18

Our heroes finally reach Sairaag. They sneak into the town under the darkness of the night and rest in the house of Sylphiel, who is one of Gourry's friends. While at the house they find out about the person who may be responsible for placing Gourry and Lina on the wanted posters. They break into the hideout of the culprit only to be ambushed by Zangulus and Vrumugun as well as one more villain, Eris, their boss. Lina slashes Vrumugun, but then she faces a man who is identical to Vrumugun. Vrumugun's true self turns out to be a clone created by Eris. When Lina is cornered by another Vrumugun, Zelgadis gallantly saves her. Is the tide turning in favor of our heroes? No, not yet. A man appears in front of them. It is Rezo. How could this be?!