The first layer is dead, insensate.
The second layer holds pain, flaring hopelessly, endlessly. The knife is barely noticed.
The third layer is hope, which is always found beside pain.
The next layers are the stories the onion tells itself. They are mostly lies, and can be disregarded.
The heart of the onion holds tears. The tears are not for itself, for its pain and sadness, its all-consuming, gnawing loneliness
The tears are for you, knife-wielder. The giver of mercy.
You are still trapped. Your heart is buried in layers.
The onion weeps, and you weep, too, never knowing why.