
Well, nothing to be explained more really than what had already been shown to us. I'm not good at explaining but I'll try lmaooo.
MC time travelled to the past, then met his younger self, which he calls, 'mini-me' (in his mind). MC has an older brother even on the 1st timeline, but that older bro, was already dead hence why he never met him again there. His older bro's name is Woo Heejae. I know this is confusing because MC was literally introduced to us as WOO HEEJAE. However, it was actually just him using his older bro's name in hopes that his brother will recognize and find him. His real name, given by his older brother, is WOO ILROK.
To simplify:
Our adult MC here uses the name Woo Heejae, and told everyone (to fool them) that he's looking for his little brother. No, he has no actual little brother. He has an older bro tho, the real Woo Heejae. The lil bro he was talking about is his younger self, real name Woo Ilrok. That's why when he called his mini self at the orphanage Ilrok, the kid immediately ran to him. Because only MC and his older brother knows their names.
In other words, MC is using his dead older brother's name and Identity. That's how there is no confusion in verse about MC and his mini self. He's literally acting like his older brother. But yes, the kid is 100% his younger self. Even to the end of the novel, he lives in this present timeline, because his 1st timeline is already ruined. So yeah, makes it more interesting, he's literally coexisting with his younger self here. I feel like I repeated myself countless times and so redundant sorry!!!
wait so like it's his younger self right? not his sibling? or maybe there's some plot twist? can you pls spoil me