Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn, you can either: Target 1 face-up "Six Samurai" monster you control; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equipped by this effect, the equipped monster gains 500 ATK and DEF. If the equipped monster destroys an opponent's monster by battle: Draw 1 card. (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed, destroy this card instead.)
--六武衆の御霊代
--Spirit of the Six Samurai
local s,id=GetID()
function s.initial_effect(c)
	aux.AddUnionProcedure(c,aux.FilterBoolFunction(Card.IsSetCard,SET_SIX_SAMURAI),true,false)
	--Atk up
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_EQUIP)
	e1:SetCode(EFFECT_UPDATE_ATTACK)
	e1:SetValue(500)
	e1:SetCondition(aux.IsUnionState)
	c:RegisterEffect(e1)
	--Def up
	local e2=e1:Clone()
	e2:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e2)
	--draw
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,2))
	e1:SetCategory(CATEGORY_DRAW)
	e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_BATTLE_DESTROYING)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e1:SetRange(LOCATION_SZONE)
	e1:SetCondition(s.drcon)
	e1:SetTarget(s.drtg)
	e1:SetOperation(s.drop)
	c:RegisterEffect(e1)
end
s.listed_series={SET_SIX_SAMURAI}
function s.drcon(e,tp,eg,ep,ev,re,r,rp)
	return aux.IsUnionState(e) and e:GetHandler():GetEquipTarget()==eg:GetFirst()
end
function s.drtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetTargetPlayer(tp)
	Duel.SetTargetParam(1)
	Duel.SetOperationInfo(0,CATEGORY_DRAW,nil,0,tp,1)
end
function s.drop(e,tp,eg,ep,ev,re,r,rp)
	if not e:GetHandler():IsRelateToEffect(e) then return end
	local p,d=Duel.GetChainInfo(0,CHAININFO_TARGET_PLAYER,CHAININFO_TARGET_PARAM)
	Duel.Draw(p,d,REASON_EFFECT)
end