make_movement_leader_effect

make_movement_leader_effect = {
	save_temporary_scope_as = new_movement_leader
	if = {
		limit = {
			any_character_situation = {
				situation_type = dynastic_cycle
				any_participant_group = {
					participant_group_has_character = scope:new_movement_leader
					NOR = { # Is not a group without a leader
						participant_group_type = hegemon_ruler
						participant_group_type = undecided_movement
						participant_group_type = other_rulers
					}
					save_temporary_scope_as = leaders_movement
				}
			}
		}
		custom_description = {
			text = make_movement_leader_effect_desc
			subject = scope:new_movement_leader
			object = scope:leaders_movement
			situation:dynastic_cycle ?= {
				random_participant_group = {
					limit = {
						participant_group_has_character = scope:new_movement_leader
					}
					set_variable = {
						name = movement_leader
						value = scope:new_movement_leader
					}
				}
			}
		}
		if = {
			limit = {
				scope:debate_loser ?= {
					this != scope:new_movement_leader
					var:movement_power < scope:new_movement_leader.var:movement_power
				}
			}
			switch = {
				trigger = scope:leaders_movement
				situation:dynastic_cycle.situation_participant_group:expansion_movement = {
					tgp_activate_catalyst_against_hegemon_effect = {
						HEGEMON = scope:new_movement_leader.top_liege
						CATALYST = catalyst_movement_gained_power_expansion
					}
				}
				situation:dynastic_cycle.situation_participant_group:advancement_movement = {
					tgp_activate_catalyst_against_hegemon_effect = {
						HEGEMON = scope:new_movement_leader.top_liege
						CATALYST = catalyst_movement_gained_power_advancement
					}
				}
				situation:dynastic_cycle.situation_participant_group:conservative_movement = {
					tgp_activate_catalyst_against_hegemon_effect = {
						HEGEMON = scope:new_movement_leader.top_liege
						CATALYST = catalyst_movement_gained_power_conservative
					}
				}
				situation:dynastic_cycle.situation_participant_group:pro_hegemon_movement = {
					tgp_activate_catalyst_against_hegemon_effect = {
						HEGEMON = scope:new_movement_leader.top_liege
						CATALYST = catalyst_movement_gained_power_pro_hegemon
					}
				}
			}
		}
	}
}

As written in game/common/scripted_effects/10_dlc_tgp_scripted_effects.txt.