Tearjerkers.

Both are about protagonists that go through major personal changes after a tragedy.

Abilities that cause them tragedy.

About protaginists with unfortunate powers that hurts them.

Both are psychological thrillers exploring someone else living inside you. Similar tone, storytelling and exceptional chemistry.

Both are psychological thrillers exploring someone else living inside you.

Both are psychological thrillers exploring someone else living inside you.

Heartwarming relationships.

Though one uses DID and the other brain surgery, the main theme of theirs is what is it like having someone else living inside you.