Game concept
Religion
The game also links it as Religious.
From the game's encyclopedia
Being passed into the next world by heathens and the sacrilegious dispatching of your mortal coil — martyrdom, crucifixion — remaining true to your faith to the very end, what more genuine way is there to pass on.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Religion is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Being passed into the next world by heathens and the sacrilegious dispatching of your mortal coil — martyrdom, crucifixion — remaining true to your faith to the very end, what more genuine way is there to pass on." It is part of Character Death. The game also links it as Religious. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.