“What We Do in the Shadows” has never been afraid to get weird. The FX comedy, based on the film by Jemaine Clement and Taika Waititi, returned Tuesday for its fourth season, with Nandor (Kayvan Novak), Nadja (Natasha Demetriou), Laszlo (Matt Berry) and Guillermo (Harvey Guillén) reunited at their Staten Island mansion.