And mind control is not his only ability (⊙…⊙ )
What do you means by his cousin? His cousin can see someone's past so I guess he know MC's past even when he was a baby.
The scientists weren't his birth parents so when they died if I'm not mistaken he went to the "parents" family. The sister was taking caring of him with mind control and he also used his powers to turn the "cousin" into an esper, if he was able to see the truth why did he still act like they were family through all these years? Why not report him? The cousin has been able to hide his abilities.
I guess he feel sympathy with MC due to past. Seeing how the cousin doesn't really attach to his mother, I assume the cousin and cousin's mother already in awkward relationship. Also, you can see her strong reaction to MC, that she doesn't want to take care another child which means the cousin's mother may not willingly take care MC's cousin too.
1. So he wasn't really their child ( wow his own mom gave him up smh)
2. The power of manipulation he has ain't even he's full powers!!! Wtf he must be the most powerful Esper in their world.
3. THEY WERE DEFINITELY MADE FOR EACH OTHER
So he's the subject that started the whole program if he's subject 000. No one know this except the seme guide. I wonder if the scientists adopted him or he used his power of manipulation on them but then again I don't understand how his cousin came into the picture. Story seems confusing now .