The ironic upbringing
The story begins with a character who belongs to the human race in a deep way. Not only is he a person with a story, he is also endowed with the knowledge of languages. He is able to read important books that others cannot because he knows Greek, Hebrew, Norse, Japanese, and Inuit. This allows him to study cultures in a deep way from a young age. He is not like a scholar who learns the languages late in life; he is an ironically young polyglot.
Ludo's fatherlessness
Although Ludo is a powerful person, he feels he needs to understand his identity in terms of his father, so he is ironically in need of his father who isn't there. The reason this desire is ironic is that of course, he is already a competent, surprisingly well-adapted young man by the time he sets off to find his father. He wants to solve his fatherless-ness, but ironically, his thirst for quest and adventure are the product of it. It is an asset in his story.
The irony of the fathers
When Ludo goes through his community to find a man who might be his father, Ludo encounters a host of men, and he tests them to see who among them might be his blood. Ironically, he finds himself disappointed, having guessed that his father would probably be a hero like himself. Instead, he finds normal men and resents that they are not who he wanted them to be. That's because, ironically, he is the hero in the community without understanding it yet. The men aren't there to save him, but vice versa.
The ironic suicide
One of the fathers is painfully in need of peace, Red Devlin. Ludo meets him as he struggles to adjust to life with his PTSD from past in Azerbaijan. When he commits suicide, that comes as a shock to him, because dramatic irony has concealed the stakes of suffering. Once he learns, he himself is somewhat traumatized, because his experience of another person's pain has imbued him with a deeper appreciation of suffering.
The irony of Yamamoto
Yamamoto is in many ways not a father figure at all. Firstly, he doesn't love Ludo, not really. He doesn't have a deep vested interest in Ludo's life, but ironically, that makes him a perfect father figure for Ludo, because it makes Ludo rise to the task of guiding his own self. He has to take responsibility for his own growth and development to belong in Yamamoto's company. Also, Yamamoto is ironic, because he allows Ludo a chance to live a fantasy of becoming a samurai.
