Can't Kill What's Already Dead

Intimidate me?
 No use, you can't harm me
 I have returned for everyone to see
 No time for empty threats
 Know the new me
 Unleash your fear, your hate
 Unhurt I will be
 Surrounded I am
 But lay down your arms and save your hate
 Immaterial being
 I'm no one you incarcerate
 I'm forever free
 Unbound by the realm of flesh
 You can't kill me
 Can't kill what's already dead
 I died long ago
 Last ship that was passing by
 Vanished where the sea meets the sky
 You chose not to hear my screams
 Turned away, escaped into your dreams
 My hands tried to get a grip
 To the very end
 Saved my last breath for a downward trip
 Sank into the ocean
 Was chained to the bottom with moral
 All my limbs were putrefied
 My body's dead, my wraith's alive
 So I'm back to intervene
 Claim revenge
 Blood is to be seen
 Nothing to lose
 No pain, no infliction
 No fear reigns inside my head
 You can't kill what's already dead