Irony of the Darkling
The Darkling is presented as the main leader of Grisha, the most powerful one and the best chance for the freedom of Ravka kingdom. Alina looks up to him and eventually falls for the Darkling unaware of his true intentions. At the end it is revealed that the Darkling is the one who created the Fold/Unsea at the first place because of his greed for power. The expectations of the Darkling as a savior alongside Alina are subverted, and he turns out to be the main antagonist of the plot making this a situational irony in the novel.
Irony of the stag and Alina’s power
The Darkling takes over Alina’s power by killing the stag and putting its antlers over her neck. There seems to be no escape for Alina and Mal from the grim fate. At the climactic ending, there is a subversion of the expected outcome. Alina takes her powers back by realizing that the mercy by not killing the stag is stronger than the Darkling’s grip over her, saves Mal and escapes.
Irony of Bahgra
Bahgra is Alina’s strict mentor that helps her bring out the power of light with her own will. In an unexpected turn of events, Bahgra is revealed to be the Darkling’s mother. She helps Alina escape after revealing the Darkling's true intentions.