My wildest fan theory is that Thaedus is Allan’s father, hear me out:
• Allan doesn’t know his father
• Allan was a test tube baby
• Thaedus and his DNA were personally involved in the creation of the scourge virus, so why not the creation of Allan??
• Allan gets stronger every time he gets beat up, same as the Viltrumites
• Thaedus makes Allan the new leader of the coalition, not someone actually qualified, which adds another layer to his embeddedness in Viltrumite culture - he upholds the idea of a monarchy, just as he upholds genocidal ideas as we see by his obsession with the scourge virus
• makes him and Mark narrative parallels as half-viltrumites with evil dads turned enemies of the Viltrum empire who left them half dead at some point
• name follows the viltrumite naming convention
I just think that unlike other Viltrumite hybrids, Unopan aesthetic characteristics tend to dominate. And that Viltrumite Unopan hybrids are like 99% genetically incompatible (because that’s how biology works) and that’s why Allan is the ONLY bio-engineered soldier. He literally won the genetic lottery combo of a very particular sperm and a very particular egg lmao
