Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If a Level 4 LIGHT monster(s) is Special Summoned to your field (except during the Damage Step): You can Special Summon this card from your GY (if it was there when the Summon resolved) or hand (even if not), but banish it when it leaves the field. You can target 1 other Level 4 LIGHT monster you control; make both that monster and this card Level 8 until the end of this turn. You can only use each effect of "Galaxy War Drake" once per turn, also you cannot Special Summon the turn you activate either of this card's effects, except LIGHT monsters.
--銀河戦竜
--Galaxy War Drake
--scripted by pyrQ
local s,id=GetID()
function s.initial_effect(c)
	--Special Summon this card from your hand or GY
	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:SetProperty(EFFECT_FLAG_DELAY)
	e1:SetCode(EVENT_SPSUMMON_SUCCESS)
	e1:SetRange(LOCATION_HAND|LOCATION_GRAVE)
	e1:SetCountLimit(1,id)
	e1:SetCondition(s.spcon)
	e1:SetCost(s.effcost)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--Change the Level of this card and another Level 4 LIGHT monster you control to 8
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_LVCHANGE)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCountLimit(1,{id,1})
	e2:SetCost(s.effcost)
	e2:SetTarget(s.lvtg)
	e2:SetOperation(s.lvop)
	c:RegisterEffect(e2)
	Duel.AddCustomActivityCounter(id,ACTIVITY_SPSUMMON,function(c) return c:IsAttribute(ATTRIBUTE_LIGHT) end)
end
function s.spconfilter(c,tp)
	return c:IsLevel(4) and c:IsAttribute(ATTRIBUTE_LIGHT) and c:IsControler(tp) and c:IsFaceup()
end
function s.spcon(e,tp,eg,ep,ev,re,r,rp)
	return eg:IsExists(s.spconfilter,1,nil,tp)
end
function s.effcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetCustomActivityCount(id,tp,ACTIVITY_SPSUMMON)==0 end
	--Cannot Special Summon, except LIGHT monsters
	local e1=Effect.CreateEffect(e:GetHandler())
	e1:SetDescription(aux.Stringid(id,2))
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET+EFFECT_FLAG_OATH+EFFECT_FLAG_CLIENT_HINT)
	e1:SetCode(EFFECT_CANNOT_SPECIAL_SUMMON)
	e1:SetTargetRange(1,0)
	e1:SetTarget(function(e,c) return not c:IsAttribute(ATTRIBUTE_LIGHT) end)
	e1:SetReset(RESET_PHASE|PHASE_END)
	Duel.RegisterEffect(e1,tp)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and c:IsCanBeSpecialSummoned(e,0,tp,false,false) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,c,1,tp,0)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) and Duel.SpecialSummon(c,0,tp,tp,false,false,POS_FACEUP)>0 then
		--Banish it when it leaves the field
		local e1=Effect.CreateEffect(c)
		e1:SetDescription(3300)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_CLIENT_HINT)
		e1:SetCode(EFFECT_LEAVE_FIELD_REDIRECT)
		e1:SetValue(LOCATION_REMOVED)
		e1:SetReset(RESET_EVENT|RESETS_REDIRECT)
		c:RegisterEffect(e1,true)
	end
end
function s.lvfilter(c)
	return c:IsLevel(4) and c:IsAttribute(ATTRIBUTE_LIGHT) and c:IsFaceup()
end
function s.lvtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	local c=e:GetHandler()
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and chkc~=c and s.lvfilter(chkc) end
	if chk==0 then return c:HasLevel() and not c:IsLevel(8)
		and Duel.IsExistingTarget(s.lvfilter,tp,LOCATION_MZONE,0,1,c) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TARGET)
	Duel.SelectTarget(tp,s.lvfilter,tp,LOCATION_MZONE,0,1,1,c)
end
function s.lvop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local tc=Duel.GetFirstTarget()
	if c:IsRelateToEffect(e) and c:IsFaceup() and c:HasLevel() and not c:IsLevel(8)
		and tc:IsRelateToEffect(e) and tc:IsFaceup() and tc:HasLevel() and not tc:IsLevel(8) then
		--Their Level becomes 8
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
		e1:SetCode(EFFECT_CHANGE_LEVEL)
		e1:SetValue(8)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		c:RegisterEffect(e1)
		local e2=e1:Clone()
		tc:RegisterEffect(e2)
	end
end