here. Usually, a first person narrator is safe - how can someone be telling us the story if he is going to die at the end of it? - although there are exceptions even to this.
I remembering discussing deaths of viewpoint characters when posting about SM Stirling's Conquistador. On a naturalistic hypothesis, we do not experience "blackness" or "darkness" after death. We do not experience period. Even when the author and his characters believe in a hereafter, to describe the hereafter is, in literary terms, to transform the narrative from mainstream fiction or any other genre into fantasy. Perfectly respectable - see Dante etc - but fantasy nonetheless. In naturalistic fiction, the viewpoint ends at death.
"The last thing he heard was thunder. It sounded like the hoofs of horses bearing westward the Hunnish midnight." (Time Patrol, p. 465)
Anderson's Ensign Conway inwardly converses with death, then we read:
"KILLED IN ACTION: Lt Cmdr Jan H. Barneveldt, Ens. Donald R. Conway, Ens. James L. Kamekona....
"MOURN FOR: Keh't'hiw-a-Suq of Dzuaq, Whiccor the Bold, Nova Rachari's Son...."
-Poul Anderson, Fire Time (St Albans, Herts, 1974), XV, p. 174.
(Different naming styles among the aliens.)
In a long battle scene in Against The Tide Of Years, SM Stirling introduces Garrett Hopkins to have him killed:
"Blackness." (p. 361)