Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
3 Level 10 monsters If this card is Special Summoned, or if another monster is Special Summoned from the GY to your field while you control this monster: You can target 1 face-up monster your opponent controls; inflict damage to your opponent equal to half its original ATK. You can only use this effect of "Phantasm Emperor Trilojig" once per turn.
--幻魔帝トリロジーグ
--Phantasm Emperor Trilojig
--Scripted by AlphaKretin, manga version updated by Larry126
local s,id=GetID()
function s.initial_effect(c)
	--Fusion material
	c:EnableReviveLimit()
	Fusion.AddProcMixN(c,false,false,aux.FilterBoolFunction(Card.IsLevel,10),3)
	--Damage
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_DAMAGE)
	e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e1:SetCode(EVENT_SPSUMMON_SUCCESS)
	e1:SetRange(LOCATION_MZONE)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET+EFFECT_FLAG_CARD_TARGET)
	e1:SetCountLimit(1,id)
	e1:SetCondition(s.damcon)
	e1:SetTarget(s.damtg)
	e1:SetOperation(s.damop)
	c:RegisterEffect(e1)
end
function s.filter(c,tp,hc)
	return c:IsControler(tp) and (c:GetPreviousLocation()==LOCATION_GRAVE or c==hc)
end
function s.damcon(e,tp,eg,ep,ev,re,r,rp)
	return eg:IsExists(s.filter,1,nil,tp,e:GetHandler())
end
function s.damtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsControler(1-tp) and chkc:IsLocation(LOCATION_MZONE) and chkc:HasNonZeroAttack() end
	if chk==0 then return Duel.IsExistingTarget(Card.HasNonZeroAttack,tp,0,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	local g=Duel.SelectTarget(tp,Card.HasNonZeroAttack,tp,0,LOCATION_MZONE,1,1,nil)
	Duel.SetTargetPlayer(1-tp)
	Duel.SetOperationInfo(0,CATEGORY_DAMAGE,nil,#g,1-tp,g:GetFirst():GetBaseAttack()/2)
end
function s.damop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	local tc=Duel.GetFirstTarget()
	if tc then
		local p=Duel.GetChainInfo(0,CHAININFO_TARGET_PLAYER)
		Duel.Damage(p,tc:GetBaseAttack()//2,REASON_EFFECT)
	end
end