Trauma

Truth.

A detective named Matt Thatcher would find Coopers dead body at an abandoned building in Lakewood, his body was mangled and mutilated, his flesh was spread on the floor and half of his skin was peeled.

With more investigation they found out that the child suffered from a mental illness. In the poor child's mind he thinks he went to an adventure with his friends to find his mother, sadly that was not the case.

Cooper suffered from trauma, this caused him to develop imaginary friends, he believed he fought the monster with his friends when in reality he didn't fight, he was alone.

His trauma was caused from a school shooting where his friends and his mother died. This led him to believe his friends and mother was still alive before Cooper went missing.

May you rest in peace, Cooper.