Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per Battle Phase, if this card attacks a Defense Position monster, it can make a second attack in a row. If this card attacks a Defense Position monster, inflict piercing battle damage to your opponent.
--ツイン・ブレイカー
--Twin-Sword Marauder
local s,id=GetID()
function s.initial_effect(c)
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_CONTINUOUS)
	e1:SetCode(EVENT_DAMAGE_STEP_END)
	e1:SetOperation(s.caop)
	c:RegisterEffect(e1)
	--pierce
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetCode(EFFECT_PIERCE)
	c:RegisterEffect(e2)
end
function s.caop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local bc=c:GetBattleTarget()
	if Duel.GetAttacker()==c and bc and (bc:GetBattlePosition()&POS_DEFENSE)~=0 and c:IsRelateToBattle() and c:CanChainAttack() then
		Duel.ChainAttack()
	end
end