Why these tropes fit

A grief-stricken witch sister wages a vengeance quest across a Sicilian underworld, venturing into forbidden dark magic while being drawn into an intoxicating and inherently dangerous romance with a demon prince she was raised to fear, where nothing about the Wicked is as it seems.

Evidence from the source

Revenge Plot: “Emilia sets out to find her sister's killer and to seek vengeance at any cost-even if it means using dark magic that's been long forbidden.” source
Angels and Demons: “Wrath, one of the Wicked-princes of Hell” source
Witchy Romance: “Emilia and her twin sister Vittoria are streghe -- witches who live secretly among humans, avoiding notice and persecution.” source
Hidden Identity: “witches who live secretly among humans, avoiding notice and persecution” source
Quest: “A quest for vengeance that will unleash Hell itself” source
Strong Heroine: “even if it means using dark magic that's been long forbidden” source
Forbidden Love: “Wrath, one of the Wicked-princes of Hell she has been warned against in tales since she was a child” source