Nightmare Fuel / Malazan Book of the Fallen

Gardens of the Moon

• The Enfilade at Pale, for the city's population and the Malaz 2nd Army. A years-long siege without open engagements is turned, at a few hours' notice, into a magical battle of mass destruction between Anomander Rake and Tayschrenn's contingent of mages. Large chunks of Moon's Spawn are splintered off and crash down on Pale, while sorcerous fire and demons sweep through the plain on which the Malazan infantry is stationed, and no one other than the mages can do a single thing to defend themselves against the indiscriminate slaughter.
• The Moranth's "hour of blood" after the Malazan victory: before any 2nd Army troops actually enter the city, the auxiliaries are allowed free rein to slaughter and torture as many people as they can within an hour, as revenge for a long-running rivalry with Pale.

Deadhouse Gates

• The Malazan Empire's gulag at Skullcup in Seven Cities, where political prisoners are forced into slave labour under unbearable conditions, killing many, and physical and sexual violence is common.

Memories of Ice

• The Rent at Morn, a wound in the fabric of the worlds that must be sealed with a soul, trapping it there in unimaginable pain unless it is replaced by another. And for hundreds of thousands of years, its captives were two children fleeing a genocide.

The Bonehunters

• The epigraph that begins the book, a poem (The Age Descending, by Torbora Fethana) filled with a sense of foreboding and dread, alluding to Rhulad Sengar's bloody reign as the Crippled God's puppet emperor of Lether:
  For all that is made real
  In this age descending
  Where heroes leave naught
  But the iron ring of their names
  From bardic throats
  I stand in this silent heart
  Yearning the fading beat
  Of lives fallen to dust
  And the sifting whisper
  Proclaims glory's passing
  As the songs fail
  In dwindling echoes
  For all that is made real
  The chambers and halls
  Yawn empty to my cries -
  For someone must
  Give answer
  Give answer
  To all of this
  Someone
• The Last Siege of Y'Ghatan. Outnumbered, without allies and out of options, Leoman of the Flails fills the walls and buildings of Y'Ghatan to the bursting with olive oil, lets the Malaz 14th Army advance far enough beyond the walls to cut off any possibility of retreat, and ignites the entire city in a conflagration devouring everything in its path. Trapped by flames in every direction, in a dark and unfamiliar urban setting with Leoman's fanatical soldiers bearing down, the Malazan soldiers flee with - seemingly - nowhere to go and many of them burn alive.
• The realisation, at the end of the first chapter of Book Four, that Mallick Rel has turned his captivity in Malaz City into an opportunity to take over the Malazan Empire. Last seen being shipped off to face justice at the end of House of Chains, Pearl finds him a prisoner in name only, in control of a vast network of agents and well on his way to persuading the Empire that he was a hero, and Coltaine the villain, of the war in Seven Cities. When Pearl announces his intent to stop him, Rel responds with a threat to the Claw, implying that there is almost no power left that could stand in his way and that Tavore and the 14th Army are returning to Malaz City to walk into a trap.
  "This rain," Mallick Rel continued behind him, "it shall make the seas rise, yes?"