Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Send 1 "Predaplant" monster from your Deck to the GY; place 1 Predator Counter on each face-up monster on the field, and if you do, any of those monsters that are Level 2 or higher become Level 1 as long as they have a Predator Counter. If you Fusion Summon a DARK monster while this card is in your GY (except during the Damage Step): You can banish this card from your GY, then target 1 card on the field; destroy it. You can only use each effect of "Predaplanning" once per turn.
--捕食計画
--Predaplanning
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCategory(CATEGORY_COUNTER)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(0,TIMING_SUMMON|TIMING_SPSUMMON)
	e1:SetCountLimit(1,id)
	e1:SetCost(s.cost)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	--set
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCategory(CATEGORY_DESTROY)
	e2:SetProperty(EFFECT_FLAG_DELAY+EFFECT_FLAG_CARD_TARGET)
	e2:SetCode(EVENT_SPSUMMON_SUCCESS)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetCountLimit(1,{id,1})
	e2:SetCost(Cost.SelfBanish)
	e2:SetCondition(s.descon)
	e2:SetTarget(s.destg)
	e2:SetOperation(s.desop)
	c:RegisterEffect(e2)
end
s.counter_place_list={COUNTER_PREDATOR}
s.listed_series={SET_PREDAPLANT}
function s.thcfilter(c)
	return c:IsMonster() and c:IsSetCard(SET_PREDAPLANT) and c:IsAbleToGraveAsCost()
end
function s.cost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.thcfilter,tp,LOCATION_DECK,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
	local g=Duel.SelectMatchingCard(tp,s.thcfilter,tp,LOCATION_DECK,0,1,1,nil)
	Duel.SendtoGrave(g,REASON_COST)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	local g=Duel.GetMatchingGroup(Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,nil)
	Duel.SetOperationInfo(0,CATEGORY_COUNTER,g,1,0,COUNTER_PREDATOR)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local g=Duel.GetMatchingGroup(Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,nil)
	local tc=g:GetFirst()
	for tc in aux.Next(g) do
		tc:AddCounter(COUNTER_PREDATOR,1)
		if tc:GetLevel()>1 then
			local e1=Effect.CreateEffect(c)
			e1:SetType(EFFECT_TYPE_SINGLE)
			e1:SetCode(EFFECT_CHANGE_LEVEL)
			e1:SetReset(RESET_EVENT|RESETS_STANDARD)
			e1:SetCondition(s.lvcon)
			e1:SetValue(1)
			tc:RegisterEffect(e1)
		end
	end
end
function s.lvcon(e)
	return e:GetHandler():GetCounter(COUNTER_PREDATOR)>0
end
function s.cfilter(c,tp)
	return c:IsAttribute(ATTRIBUTE_DARK) and c:GetSummonPlayer()==tp and c:IsFusionSummoned()
end
function s.descon(e,tp,eg,ep,ev,re,r,rp)
	return eg:IsExists(s.cfilter,1,nil,tp)
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsOnField() end
	if chk==0 then return Duel.IsExistingTarget(aux.TRUE,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
	local g=Duel.SelectTarget(tp,aux.TRUE,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,g,1,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.Destroy(tc,REASON_EFFECT)
	end
end