In the darkness, I stay hidden, then with the cleansing sweep,
I step out from the shadows, as I watch the whole world weep.
I was torn apart, my body bent, forever segregated.
Broken, I at first give life. Then as a weapon, take it.
Elusive, you won't trap me, nor the hoard kept at my feet,
Sometimes haunted by my twin, though cursed to never meet.
Riding on your gallows, bathed in violence, I start.
Say my name, mere mortal, before I again depart.
You are a:
RAINBOW
In the darkness, I stay hidden, then with the cleansing sweep,
The "cleansing sweep" refers to the rain. "In the darkness" means that it cannot be seen (unless under some certain conditions).
I step out from the shadows, as I watch the whole world weep.
The rainbow emerges from nowhere. The "world weeping" again refers to the rain.
I was torn apart, my body bent, forever segregated.
"Body bent" refers to the shape of the rainbow.
Broken, I at first give life. Then as a weapon, take it.
"Broken" refers perhaps to the division of the colours of the rainbow. "At first give life" refers to RAIN, "then as a weapon take it" refers to BOW.
Elusive, you won't trap me, nor the hoard kept at my feet,
You cannot contain a rainbow. There is said to be a pot of gold at the end (or "feet") of the rainbow.
Sometimes haunted by my twin, though cursed to never meet.
Sometimes there is a second rainbow on a wider arc.
Riding on your gallows, bathed in violence, I start.
ROYGBIV...
Say my name, mere mortal, before I again depart.
I said already dammit! RAINBOW!
As a personal comment: This is a world class riddle.
I see (and like!) the accepted answer, but here's what I came up with that I think is also pretty reasonable:
Sub-atomic matter, particularly in the context of the atomic bomb.
In the darkness, I stay hidden,
These particles are extremely hard to detect, plus you have the whole quantum debacle
then with the cleansing sweep,
The detonation of an atomic bomb.
I step out from the shadows, as I watch the whole world weep.
The weaponizing of an atomic bomb is very visible, but also extremely tragic if used to take lives.
I was torn apart, my body bent, forever segregated.
The atom as a whole is torn apart. Not sure about the bent part. The weaponizing of atomic bombs in WW2 creates a 'permanent segregation' of sorts -- there are 'prewar' and 'postwar' eras.
Broken, I at first give life. Then as a weapon, take it.
Big bang, etc., vs. weaponization of atomic energy.
Elusive, you won't trap me, nor the hoard kept at my feet,
We can't ever know the position and velocity of a sub-atomic particle simultaneously, so they're elusive and 'untrappable'. The hoard at its feet could be those new-fangled particles like gluons and such.
Sometimes haunted by my twin, though cursed to never meet.
Anti-matter
Riding on your gallows, bathed in violence, I start.
Again, bomb stuff
Say my name, mere mortal, before I again depart.
As more regulations and treaties are signed, the chances of future nuclear war diminishes.
I think you are referring to
Batman: He's the silent guardian, a watchful protector, The dark knight.
In the darkness, I stay hidden, then with the cleansing sweep,
I step out from the shadows, as I watch the whole world weep.
Batman is a symbol of clandestine in the darkness, the secret identity of Bruce Wayne. Mere mortals, except the fortunate few are ignorant of his identity. He keeps a hawk eye as a watchful protector over Gotham, rising from the dark whenever the city is on the verge of catastrophic destruction.
I was torn apart, my body bent, forever segregated.
Broken, I at first give life. Then as a weapon, take it.
This has a particular reference to the filmographic representation of the Batman story as The Dark Knight Rises. In that film, Selina delivers Batman to Bane, often called The Mask, who cripples him and throws him to a well like prison which was seemingly impossible to escape. The weapon referred I believe is the fusion reactor which was supposed to take over gotham.
Elusive, you won't trap me, nor the hoard kept at my feet,
Sometimes haunted by my twin, though cursed to never meet.
Here
by my twin, I think it was a reference to Robin. Ohh, and did I say mere Mortals were unable to trap and track him?
Riding on your gallows, bathed in violence, I start.
Say my name, mere mortal, before I again depart.
Again, it is the reference to the film The Dark Knight where he took up the responsibility of the death of Harvy Dent, the two face.
