This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / The Neo Domino Purge
The fic has its share of Family Unfriendly Deaths: Takasu falls through the height of the Detention Centre and is pretty much flattened by the impact once he hits the ground. Judge shares a similar fate and is flung from a severed highway in Satellite when his D-Wheel malfunctions and fails to brake properly, while Ushio is Buried Alive after a duel with Jack.
Ushio's is elaborated on in Chapter 35, by his describing how he was impaled by debris and had no way of escaping his grave, succumbing eventually to suffocation and blood loss.
Yusei's Bad Dreams takes the elements of the one from the anime and cranks up the horror: he's confronted by Kiryu, who stands over the bodies of the other Signers. Each one is described as having died in a brutal fashion; Jack having lost his left arm, Aki in a pool of her own blood and Ruka being choked. Yusei finds himself impaled by the debris that almost caused him to die and is on his knees, watching as Kiryu launches an attack against him with the very monster he's terrified of.