mpo_execution_head_artifact_creation_effect

mpo_execution_head_artifact_creation_effect = {
	save_scope_as = owner
	#This is an emperor's head
	if = {
		limit = {
			has_character_flag = execution_head_illustrious_flag
		}
		create_artifact = {
			name = executed_head_artifact
			description = executed_head_emperor_artifact_desc
			rarity = illustrious
			type = miscellaneous
			modifier = artifact_monthly_prestige_gain_per_dread_add_4_modifier
			decaying = yes
			template = mpo_severed_head_template
			visuals = pocket_severed_head
			creator = scope:victim
			save_scope_as = head_artifact
		}
	}
	else = {
		create_artifact = {
			name = executed_head_artifact
			description = executed_head_king_artifact_desc
			rarity = famed
			type = miscellaneous
			modifier = artifact_monthly_prestige_gain_per_dread_add_3_modifier
			decaying = yes
			template = mpo_severed_head_template
			visuals = pocket_severed_head
			creator = scope:victim
			save_scope_as = head_artifact
		}
	}
	if = {
		limit = {
			scope:head_artifact = {
				NOT = {
					artifact_owner = {
						this = root
					}
				}
			}
		}
		scope:head_artifact = {
			set_owner = root
		}
	}

	random_list = {
		4 = {
			trigger = {
				OR = {
					is_at_war_with = scope:headless_heir
					is_causing_raid_hostility_towards = scope:headless_heir
				}
			}
			scope:head_artifact = {
				add_2_scaled_artifact_modifier_combat_effect = yes
			}
		}
		1 = {
			trigger = {
				scope:headless_heir = {
					government_has_flag = government_is_nomadic
				}
			}
			scope:head_artifact = {
				add_scaled_artifact_modifier_archer_cavalry_damage_add_effect = yes
				add_scaled_artifact_modifier_minor_prestige_effect = yes
			}
		}
		1 = {
			trigger = {
				OR = {
					scope:victim.faith = {
						NOT = {
							this = root.faith
						}
					}
					scope:victim = {
						has_trait = zealous
					}
					scope:victim = {
						has_trait = pilgrim
					}
					scope:headless_heir.primary_title = {
						is_head_of_faith = yes
					}
				}
			}
			scope:head_artifact = {
				add_scaled_artifact_modifier_piety_effect = yes
			}
			scope:head_artifact = {
				add_scaled_artifact_modifier_devotion_effect = yes
			}
		}
		1 = {
			trigger = {
				OR = {
					scope:victim.faith = {
						NOT = {
							this = root.faith
						}
					}
					scope:victim = {
						has_trait = zealous
					}
					scope:victim = {
						has_trait = pilgrim
					}
					scope:headless_heir.primary_title = {
						is_head_of_faith = yes
					}
				}
			}
			scope:head_artifact = {
				add_2_scaled_artifact_modifier_devotion_effect = yes
			}

As written in game/common/scripted_effects/09_dlc_mpo_scripted_effects.txt.