So, I will put two things in here before the story starts:
First, this will take place during recent times, so "harry" will be born at 2002
Second, this is a somewhat humor oriented fic, but it will get dark eventauly, and voldemort wont become a good guy by being in proximinty to others, he is and will be a self-serving asshole
Parasitic immortality, the ability to transfer your consciousness to other bodies.
Voldemort has briefly thought about trying this method for immortality, but stopped thinking about it once he realized that it wouldn't make him immortal, just eternally young, how he would even begin to transfer his entire mind whiteout the targets brain frying, them resisting and the mind of the target and his own "breaking" each other or his mind being plain out rejected and his mind becoming an ever drifting ghost anyways?
And it wasn't like he was on a time limit, he was winning against Dumbledore, and he already had 6 of his horcruxes, he only had one more to make to get seven. He was practically invincible by now!
That was what he thought, until Snape told him about the prophecy, he didn't panic, the part of the prophecy he heard didn't say he would die to the potter's child, it simply said that he would have the power to vanquish him: "The one with the power to vanquish the Dark Lord approaches... born to those who have thrice defied him, born as the seventh month dies... ". There were two children which fit the description, but he chose the ones who were actually a danger. He sent Bellatrix to kill the other child.
Pettigrew told him where the potter's lived; all he needed to do is take care of the child before it grew up. (and in his hurry he failed to realize that the prophecy directly stated that the child would have the power to vanquish him)
In fact, he instead prepared to make another horcrux, it would be thematic to get his immortality from his greatest threat
He could have sent minions, he should have sent minions. But he didn't, because he remembered stories about the big bad guys sending minions when they could do it themselves better… and he did well, he killed Potter easily, he killed the muggleborn easily, and once he got to the baby, he cast an Avada Kedavra, feeling almost stupid for having been worried… and then the spell bounced back at him. Avada Kedavra does not bounce back. But deny it he might want, it did. And he felt his soul break apart, his life being used to make another horcrux.
Horcrux affected sentient beings differently than objects; it made mold the mind to be like the soul that was put inside them.
The child was used to make a horcrux, he felt he's soul being ripped apart, with the main soul being thrown out of his body, and the remaining being forced into the child.
He could feel a barrier of kinds trying to reject him, but in panic for his life, he forced all of his power to push the soul inside the child.
And now, here he was, the "mind" of the child being molded after his own, confused, unable to see or hear properly. Afraid of being found out, he made barriers around his mind containing false memories.
And so, Voldemort, Tom Marvolo Riddle, being reborn as Harry Potter, the boy who lived