Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can Tribute 1 face-up Level 3 or lower monster on your opponent's side of the field to Special Summon this card to your opponent's side of the field. If you Special Summon this monster this way, place 1 A-Counter on this card, and you cannot Normal Summon or Set the same turn. (If a monster with an A-Counter battles an "Alien" monster, it loses 300 ATK and DEF for each A-Counter during damage calculation only.)
--エーリアン・スカル
--Alien Skull
local s,id=GetID()
function s.initial_effect(c)
	--special summon
	local e1=aux.AddLavaProcedure(c,1,POS_FACEUP,aux.AND(Card.IsFaceup,aux.FilterBoolFunction(Card.IsLevelBelow,3)),1)
	--counter
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_COUNTER)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_CONTINUOUS)
	e2:SetCode(EVENT_SPSUMMON_SUCCESS)
	e2:SetCondition(s.ctcon)
	e2:SetOperation(s.ctop)
	c:RegisterEffect(e2)
	--atk def
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD)
	e3:SetCode(EFFECT_UPDATE_ATTACK)
	e3:SetRange(LOCATION_MZONE)
	e3:SetTargetRange(LOCATION_MZONE,LOCATION_MZONE)
	e3:SetCondition(s.adcon)
	e3:SetTarget(s.adtg)
	e3:SetValue(s.adval)
	c:RegisterEffect(e3)
	local e4=e3:Clone()
	e4:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e4)
	--
	local e5=Effect.CreateEffect(c)
	e5:SetType(EFFECT_TYPE_SINGLE)
	e5:SetCode(EFFECT_SPSUMMON_COST)
	e5:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
	e5:SetCost(s.spcost)
	e5:SetOperation(s.spcop)
	c:RegisterEffect(e5)
end
s.listed_series={SET_ALIEN}
s.counter_place_list={COUNTER_A}
function s.spcost(e,c,tp,sumtype)
	return sumtype ~= SUMMON_TYPE_SPECIAL+1 or Duel.GetActivityCount(tp,ACTIVITY_NORMALSUMMON)==0
end
function s.spcop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_CANNOT_SUMMON)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e1:SetReset(RESET_PHASE|PHASE_END)
	e1:SetTargetRange(1,0)
	Duel.RegisterEffect(e1,tp)
	local e2=e1:Clone()
	e2:SetCode(EFFECT_CANNOT_MSET)
	Duel.RegisterEffect(e2,tp)
end
function s.ctcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():GetSummonType()==SUMMON_TYPE_SPECIAL+1
end
function s.ctop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsFaceup() then
		c:AddCounter(COUNTER_NEED_ENABLE+COUNTER_A,1)
	end
end
function s.adcon(e)
	return Duel.IsPhase(PHASE_DAMAGE_CAL) and Duel.GetAttackTarget()
end
function s.adtg(e,c)
	local bc=c:GetBattleTarget()
	return bc and c:GetCounter(COUNTER_A)~=0 and bc:IsSetCard(SET_ALIEN)
end
function s.adval(e,c)
	return c:GetCounter(COUNTER_A)*-300
end