ep3_greek_fire_success_effect

ep3_greek_fire_success_effect = {
	scope:invading_commander ?= {
		add_character_modifier = {
			modifier = ravaged_by_greek_fire_modifier
			years = 1
		}
		add_stress = major_stress_impact_gain
	}
	scope:army = {
		deplete_army_by_percentage = 0.9
	}
	scope:invader ?= {
		custom_tooltip = two_knights_killed_tooltip
		hidden_effect = {
			scope:knight_1 ?= {
				death = {
					death_reason = death_greek_fire
					killer = scope:city_defender
				}
			}
			scope:knight_2 ?= {
				death = {
					death_reason = death_greek_fire
					killer = scope:city_defender
				}
			}
		}
		custom_tooltip = three_knights_killed_tooltip
		hidden_effect = {
			scope:knight_3 ?= {
				increase_wounds_effect = { REASON = greek_fire }
			}
			scope:knight_4 ?= {
				increase_wounds_effect = { REASON = greek_fire }
			}
			scope:knight_5 ?= {
				increase_wounds_effect = { REASON = greek_fire }
			}
		}
	}
}

As written in game/common/scripted_effects/07_dlc_ep3_scripted_effects.txt.