Why did Sephiroth becomes evil?

[Sharon]

Sephiroth use the a Hero, Cloud even use to Idolize him. I know he seemed to have mommy issues because he snapped when he found out that he is just a clone of a dead frozen woman the people from Shinra found. Is that justifiable for him to want to destroy Gaia, His home planet just because he is artificial human who is clone by some dead lady who is lifeless for millenia.

 

[Barida]

He wanted to become God and the only way to make that happen is for him to merge with the lifestream which will cause deaths of billions of people.

 

[Drake]

He wanted vengeance on Shinra and the entire world, and it just so happened that he had the means to do so.
He was the most powerful person on the planet, and he clearly desired to increase his power.

 

[CindyLuStar]

Sephiroth was said to have spent the majority of his childhood at the Shinra Science Department. Everything he knew came from books and various experiments on him. He was more or less alone for the most part, with only the cold and inhuman Hojo as a parent figure. Based on the subtle subtext of the various conversations he has prior to the Nibelheim fire, Sephiroth had an inferiority complex about not knowing where he came from.

It basically drove him insane because he had existential crisis.

 

[Kitty]

Him not being full human gave him lack of Empathy. Look at him killing Aerith in cold Blood like its nothing.

 

[Mama Cathy]

He have extreme mommy issues and it snaps when he found out his real mother is an ancient corpse.

 

[kevinfeb4]

In the Final Fantasy series, Sephiroth is my favorite villain. His song is epic, and he can fight even when he is dead, though he is more powerful as you will see at the end of the game. Cloud always beats him, but he always comes back. By cloning himself and resurrecting him in some way. It's just his strength at the end of the game. It's simply not fair for Cloud, but I believe the stronger he becomes, the better.

 

[XCORPION]

And now I've played the remake, I understand why the story isn't identical. Sephiroth's power extends beyond death; he always finds a way to return, so he has discovered a way to change the timeline. However, the fate ghosts are attempting to stop him, so he enlists the help of Cloud and the gang to get rid of them so he can manipulate events to his advantage.

 

[Dictator20]

Remember those teenagers who rebels when they found out they are adopted. Sepiroth is like that.

 

[LpNrW100]

He's never even been held by his own mother, which is tragic. It's no surprise he's the way he is, and one almost feels sorry for him. I don't blame him for bringing Shinra down.