Kingdom Hearts III: Prologue

The light represents those who fight for the sake of others

Including oneself

The darkness is those who wish for destruction

Evil is an inevitability and will always thrive in the darkness

The darkness, however, is merely a medium

It is merely easier to hide in the dark

The darkness is not to blame

New evil will always rise, possibly from an old enemy

But with new enemies comes new friend who can help

And the light can show the shadows of the past and reveal new things

Some good, and some bad

Corruption is a virus that can affect even the strong

Fear not

The heart is a harder thing to corrupt

The strongest of hearts can weather the illusion of corruption and see past it all

To the truth

The true origin of the corruption is the strongest entity

All past experiences will be called upon and you must fight

Or all existence will be doomed