Eternal Sabbath

The young man was created in a lab, given a gene called ES - Eternal Sabbath. As a result, he will live to be two hundred years old. He has the power to enter your mind and make you think you've known him your whole life - or forget him, however he wills. He is known as Shuro, though he has taken other names as he needs. Today, he is Ryousuke Akiba.

A series of events brings Shuro to the attention of a brain researcher named Dr. Mine Kujou. She is resistant to his powers, which arouses his interest. However, at the same time, she encounters another resistant - Sakaki, a researcher from the laboratory that created Shuro... the last survivor, as it so happens.

For the lab that created Shuro also created a clone, Isaac. The intention was to dissect Isaac in order to study what exactly makes an ES tick. But when Isaac discovered this plan, he rebelled and killed everyone in the lab whom he could before escaping.

Isaac's still out there. He has no empathy for any human being. If he is not stopped, the consequences could be nightmarish. And Shuro is the only one who can truly stop him.

Now how will they convince Shuro of that?

Eternal Sabbath is an eight-volume manga by Fuyumi Soryo, who previously did MARS.

Tropes used in Eternal Sabbath include:

Abusive Parents - Yuri's mother beats her the same way her father beat her.
Anyone Can Die - Out of the named characters, Mine, Sakaki and Mrs. Akiba are the only survivors at the end.
Berserk Button - Abortion reminds Isaac far too much of his original fate.
Cloning Blues - Isaac was created for the sole purpose of being killed and studied.
Creating Life Is Bad - Exemplified by Isaac.
Designer Babies - While it's never clear exactly to what degree Shuro was artificially created, both he and Isaac were genetically altered to implant the Eternal Sabbath gene.
Enfante Terrible - Isaac, who kills people because they bother him and looks all of ten years old.
Evil Counterpart - Isaac is this to Shuro - they even share the same genetic code.
Freudian Excuse - Even the other characters admit Isaac has a good reason to be like he is.
Good Girls Avoid Abortion - Subverted with Yuri's mother.
Grand Theft Me - Isaac does this to Shuro... but doesn't realize that Shuro jumped out of Isaac's body before it was destroyed.
Infant Immortality - Averted; Isaac kills a lot of kids over the course of the series. Even Yuri.
Pet the Dog - Mine adopts a one-eyed dog at one point to save him from being put to sleep. Later, after sleeping with her, Shuro befriends the dog as well... without using his powers.
Psychic-Assisted Suicide - Isaac likes to trigger these in the people who irritate him. Shuro has to do this once or twice, as well.
Psychic Powers - Shuro and Isaac can both manipulate memories, read thoughts and emotions, and plant hypnotic suggestions.
Someone to Remember Him By - The last page of the manga shows Mine learning she's pregnant with the late Shuro's child. There is the slight possibility that Shuro's mind is in the fetus.
Taking You with Me - Dying from an autoimmune disorder that's given him progeria, Isaac decides to destroy as much of the city as he can in his "death throes".
Younger Than They Look - Shuro's only fifteen or so. Isaac is around five. Both look twice their age.