Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Each time an opponent's monster effect is activated, place 1 Spell Counter on this card when that effect resolves. You can send this card with 6 or more Spell Counters to the GY; add 1 Spell from your Deck to your hand. You can only use this effect of "Mythical Bestiamorph" once per turn.
--魔導変換
--Mythical Bestiamorph
local s,id=GetID()
function s.initial_effect(c)
	--counter permit
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_COUNTER_PERMIT+COUNTER_SPELL)
	e1:SetValue(LOCATION_SZONE)
	e1:SetCondition(s.ctcon)
	c:RegisterEffect(e1)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--add counter
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_CONTINUOUS+EFFECT_TYPE_FIELD)
	e2:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
	e2:SetCode(EVENT_CHAINING)
	e2:SetRange(LOCATION_SZONE)
	e2:SetOperation(aux.chainreg)
	c:RegisterEffect(e2)
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_CONTINUOUS+EFFECT_TYPE_FIELD)
	e3:SetCode(EVENT_CHAIN_SOLVED)
	e3:SetRange(LOCATION_SZONE)
	e3:SetOperation(s.acop)
	c:RegisterEffect(e3)
	--search
	local e4=Effect.CreateEffect(c)
	e4:SetCategory(CATEGORY_TOHAND+CATEGORY_SEARCH)
	e4:SetType(EFFECT_TYPE_QUICK_O)
	e4:SetCode(EVENT_FREE_CHAIN)
	e4:SetRange(LOCATION_SZONE)
	e4:SetCountLimit(1,id)
	e4:SetCondition(s.thcon)
	e4:SetCost(Cost.SelfToGrave)
	e4:SetTarget(s.thtg)
	e4:SetOperation(s.thop)
	c:RegisterEffect(e4)
end
s.counter_place_list={COUNTER_SPELL}
function s.ctcon(e)
	return e:GetHandler():IsStatus(STATUS_EFFECT_ENABLED)
end
function s.acop(e,tp,eg,ep,ev,re,r,rp)
	local p=Duel.GetChainInfo(ev,CHAININFO_TRIGGERING_PLAYER)
	local c=e:GetHandler()
	if re:IsMonsterEffect() and p~=tp and c:GetFlagEffect(1)>0 then
		c:AddCounter(COUNTER_SPELL,1)
	end
end
function s.thcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():GetCounter(COUNTER_SPELL)>=6
end
function s.thfilter(c)
	return c:IsSpell() and c:IsAbleToHand()
end
function s.thtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.thfilter,tp,LOCATION_DECK,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,nil,1,tp,LOCATION_DECK)
end
function s.thop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATOHAND)
	local g=Duel.SelectMatchingCard(tp,s.thfilter,tp,LOCATION_DECK,0,1,1,nil)
	if #g>0 then
		Duel.SendtoHand(g,nil,REASON_EFFECT)
		Duel.ConfirmCards(1-tp,g)
	end
end