If this card is sent from your hand or Deck to your GY by an opponent's card effect: Special Summon this card.
Rulings
Individual Card FAQs
"Despair from the Dark" can be Normal Summoned.
Only the owner of "Despair from the Dark" can use its effect, because it has to be sent from your hand to your Graveyard.
When you discard "Despair from the Dark" with "Painful Choice", "Despair from the Dark"'s effect does not activate because it was your own card effect that caused it.
If "Despair from the Dark" is sent to the Graveyard during a card effect's resolution, or during a chain, activate "Despair from the Dark"'s effect after the current effect or chain has resolved.
If "Despair from the Dark" is sent to the Graveyard by "Last Turn"'s effect, "Despair from the Dark" is Special Summoned to the field before the attack of "Last Turn" happens.
Netrep Rulings
If "Despair from the Dark" is sent to the Graveyard as a result of "Morphing Jar #2's" effect, "Despair from the Dark's" effect will activate since the monster is considered being sent from the Deck to the Graveyard.
DARK|
Level 8|[ Zombie / Effect ]
ATK 2800|
DEF 3000