Game concept · All Under Heaven
Dynastic Cycle Catalyst
The game also links it as Dynastic Cycle Catalysts, Dynastic Cycle Catalyst's, Dynastic Cycle Catalysts'.
From the game's encyclopedia
Certain Situations transition between Situation Phases when a Situation Catalyst occurs.
A list of which Situation Catalyst are important in each Situation Phase can be found in the Situation window.
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.
Dynastic Cycle Catalyst is an entry of Crusader Kings III's in-game encyclopedia (All Under Heaven). The game explains it: "Certain Situations transition between Situation Phases when a Situation Catalyst occurs." It is part of Situation Catalyst. The game also links it as Dynastic Cycle Catalysts, Dynastic Cycle Catalyst's and Dynastic Cycle Catalysts'. Patch 1.20.1.2, from game/common/game_concepts/tgp_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/tgp_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.