Guillermo may be the more mild-mannered individual living in the vampires’ Staten Island mansion, but as Harvey puts it, “He does have the power and he’s overpowered Nandor, at this point, twice. He could destroy him.”
After Guillermo discovers that he is related to Abraham Van Helsing, the famous vampire hunter who first appeared in Bram Stoker’s Dracula novel, the dynamic changes between him and his roommates completely.
Source: https://www.distractify.com/p/guillermo-what-we-do-in-the-shadows-actor