@JasmineFlower
Thanks a lot!
But there was also some other kid that was related to the hole, right?
I will trust your recommendation and check out Distant Sky, thanks
Yes, there was a girl that fell into a Hole, disappeared for a while and came back all messed up and insane, but also super-powerful. Her case is what started the whole Imagine Project - an attempt to recreate her mysterious powers artificially. She eventually died on her own while mumbling something about White.
Our MC was the son of the doc and his wife, but he supposedly died of some illness and was buried, only to mysteriously reappear on the couple's door after a few days, like nothing had happened. The doc dug out his grave with Lilia and discovered one of the Holes there.
BTW aside from the revival event, the MC also was injected with the Violet factor by his mother, though it apparently didn't do anything before he came back to life.
If you read Distant Sky, it's implied the Holes are actually wormholes and may connect to the past or future, though I have no idea where the one from the grave connected to. Was it created by White or someone else? Unclear as of yet.