Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When you Xyz Summon a monster: You can Special Summon this card from your hand. Once per turn: You can detach 1 Xyz Material from a monster you control, then target 1 face-up Xyz Monster on the field; reduce its Rank by 1, and if you do, it loses 300 ATK.
--黄血鬼
--Yellow-Bellied Oni
local s,id=GetID()
function s.initial_effect(c)
	--spsummon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e1:SetRange(LOCATION_HAND)
	e1:SetCode(EVENT_SPSUMMON_SUCCESS)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
	--rankdown
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetCountLimit(1)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCost(s.rdcost)
	e2:SetTarget(s.rdtg)
	e2:SetOperation(s.rdop)
	c:RegisterEffect(e2)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	local c=eg:GetFirst()
	return #eg==1 and c:IsControler(tp) and c:IsXyzSummoned()
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and e:GetHandler():IsCanBeSpecialSummoned(e,0,tp,false,false) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,e:GetHandler(),1,0,0)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if not c:IsRelateToEffect(e) then return end
	Duel.SpecialSummon(c,0,tp,tp,false,false,POS_FACEUP)
end
function s.rdcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.CheckRemoveOverlayCard(tp,1,0,1,REASON_COST) end
	Duel.RemoveOverlayCard(tp,1,0,1,1,REASON_COST)
end
function s.filter(c)
	return c:IsFaceup() and c:GetRank()>1
end
function s.rdtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and s.filter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TARGET)
	Duel.SelectTarget(tp,s.filter,tp,LOCATION_MZONE,LOCATION_MZONE,1,1,nil)
end
function s.rdop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) and tc:IsFaceup() then
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(-300)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD)
		tc:RegisterEffect(e1)
		local e2=e1:Clone()
		e2:SetCode(EFFECT_UPDATE_RANK)
		e2:SetValue(-1)
		tc:RegisterEffect(e2)
	end
end