Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can only control 1 "War Rock Ordeal". When this card is activated: Place 3 counters on it. When your "War Rock" monster destroys an opponent's monster by battle and sends it to their GY: You can remove 1 counter from this card, and if you do, draw 1 card. If the last counter has been removed by this effect, send this card to the GY.
--ウォークライ・オーディール
--War Rock Ordeal
local s,id=GetID()
function s.initial_effect(c)
	c:SetUniqueOnField(1,0,id)
	c:EnableCounterPermit(0x205)
	--place counters on activation
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_COUNTER)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetOperation(s.actop)
	c:RegisterEffect(e1)
	--remove counter + draw
	local e2=Effect.CreateEffect(c)
	e2:SetCategory(CATEGORY_COUNTER+CATEGORY_DRAW)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_BATTLE_DESTROYED)
	e2:SetRange(LOCATION_SZONE)
	e2:SetCondition(s.dcon)
	e2:SetTarget(s.dtg)
	e2:SetOperation(s.dop)
	c:RegisterEffect(e2)
	--to GY when last counter is removed
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e3:SetCode(EVENT_REMOVE_COUNTER+0x205)
	e3:SetRange(LOCATION_SZONE)
	e3:SetCondition(s.tgcon)
	e3:SetOperation(s.tgop)
	c:RegisterEffect(e3)
end
s.listed_names={id}
s.listed_series={SET_WAR_ROCK}
s.counter_place_list={0x205}
--place counters on activation
function s.actop(e,tp,eg,ep,ev,re,r,rp)
	if not e:GetHandler():IsRelateToEffect(e) then return end
	e:GetHandler():AddCounter(0x205,3)
end
--remove counter + draw
function s.dcon(e,tp,eg,ep,ev,re,r,rp)
	local tc=eg:GetFirst()
	local rc=tc:GetReasonCard()
	return #eg==1 and rc:IsControler(tp) and tc:IsMonster() and tc:IsReason(REASON_BATTLE) and tc:IsLocation(LOCATION_GRAVE) and rc:IsSetCard(SET_WAR_ROCK)
end
function s.dtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsPlayerCanDraw(tp,1) and e:GetHandler():IsCanRemoveCounter(tp,0x205,1,REASON_EFFECT) end
	Duel.SetOperationInfo(0,CATEGORY_COUNTER,e:GetHandler(),1,tp,LOCATION_SZONE)
	Duel.SetOperationInfo(0,CATEGORY_DRAW,nil,1,tp,LOCATION_DECK)
end
function s.dop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local ct=c:GetCounter(0x205)
	e:GetHandler():RemoveCounter(tp,0x205,1,REASON_EFFECT)
	if c:GetCounter(0x205)<ct then
		Duel.RaiseEvent(c,EVENT_REMOVE_COUNTER+0x205,e,REASON_EFFECT,tp,tp,1)
		Duel.Draw(tp,1,REASON_EFFECT)
	end
end
--to GY when last counter is removed
function s.tgcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():GetCounter(0x205)==0
end
function s.tgop(e,tp,eg,ep,ev,re,r,rp)
	Duel.SendtoGrave(e:GetHandler(),REASON_EFFECT)
end