Every player got to ask Death one question about how he foresaw each of the gods' deaths. It seems you only got this option if Death killed Gielinor during Nomad's Elegy. He appeared in the labyrinth.
These were collected from other people who have posted on the thread and JivaSoul, a transcriptor. below:
(tl;dr Armadyl and Seren's deaths are the only ones that the most painless, while Icthlarin's was the most gruesome.)
Icthlarin: "Poor Icthlarin, I feared looking into his future… His end is painful. The rending of teeth, the taste of blood. He dies fearing for others, and that is what truly kills him. Though it breaks my oath, I will never let that happen. I can’t let him feel that kind of pain. "
Credit: JivaSoul
Armadyl: "I feel the lightness of my being, soaring perhaps, and then a fall. I let the ground take me. But this is not a sad moment, I am full of pride." Credit: JivaSoul
Zaros: "I feel a burning as hot as a star, and then a giant blackness. I feel a prolonged sadness that has come to an end. Credit: JivaSoul"
Zamorak: "I feel a great burden of the rock, none will witness it, only crickets chirping, there will be only sadness in the end." Credit: Kanarthasis
Saradomin: "I hear the crossing of swords and the warmth of light, then the coolness of shadow. These continue, light then shadow, until I pass. Credit: JivaSoul"
Seren: "I feel relief, the joy of acceptance. There is singing, so loud that I can barely think. My mind is on the past." Credit: mghtymth