Got thinking again about Monodramon being Raito's mirror reflection and them having no confidence in themselves, and while I'm at it I might as well post the theory I've had for a bit about that relating to the circumstances of Monodramon's birth/why their personality and temperament ended up so different from Raito.
That is, I point to an example of another digimon whom we see the birth of and end up with very different temperaments to their tamer.
Shiitake, RedVeggiemon's owner, isn't usually a particularly violent or vengeful person, he showed that when he inevitably went against RedVeggiemon in the episode. RedVeggiemon was like that because they were born from Shiitake's violent desire for revenge and that feeling was so strong that it made RedVeggiemon's entire personality very violent and sadistic.
Now let's go back to Monodramon. Monodramon has no confidence in themself but Raito is shown to be incredibly confident. Some people have said that this must mean Raito's confidence was faked and Monodramon's lack of self confidence is closer to what his true self is like but I don't think this is the case. I've also seen people say that his unwavering faith in Raito is meant to represent how much confidence Raito has in himself, but I think that part is just a byproduct of how their two personalities would naturally mix together (aka Monodramon who has no confidence started to rely on Raito and his confidence).
Instead, I think it's a similar case to RedVeggiemon, where it's more related to the circumstances that caused Monodramon's birth. Raito is usually very confident so for Monodramon to have ended up with no self confidence, the moment of Monodramon's birth must be a moment of severe insecurity and self doubt for him just like the moment of RedVeggiemon's birth being Shiitake in the middle of being very consumed by the desire for revenge.
My personal theory was that he was close to getting to the Egg like his parents wanted for him but the pressure was starting to catch up to him and he starts to doubt if he could actually do it. Basically Monodramon was born during a moment of weakness for Raito and they represent Raito's insecurity, his self doubt, his cry for help that he can't meet the high standards he and everyone else have set for himself.