Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If this card attacks an opponent's monster, this card gains 400 ATK during the Damage Step only. If this card destroys an opponent's monster by battle, until your next Standby Phase: this card becomes Level 2 and its original ATK and DEF are halved.
--マックス・ウォリアー
--Max Warrior
local s,id=GetID()
function s.initial_effect(c)
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCode(EFFECT_UPDATE_ATTACK)
	e1:SetCondition(s.condtion)
	e1:SetValue(400)
	c:RegisterEffect(e1)
	--addown
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
	e2:SetCategory(CATEGORY_ATKCHANGE)
	e2:SetCode(EVENT_BATTLE_DESTROYING)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCondition(s.atkcon)
	e2:SetOperation(s.atkop)
	c:RegisterEffect(e2)
end
function s.condtion(e)
	local ph=Duel.GetCurrentPhase()
	return (ph==PHASE_DAMAGE or ph==PHASE_DAMAGE_CAL)
		and Duel.GetAttacker()==e:GetHandler() and Duel.GetAttackTarget()~=nil
end
function s.atkcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():IsRelateToBattle() and e:GetHandler():IsFaceup()
end
function s.atkop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToBattle() and c:IsFaceup() then
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_SET_BASE_ATTACK)
		e1:SetValue(c:GetBaseAttack()/2)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD_DISABLE|RESET_PHASE|PHASE_STANDBY|RESET_SELF_TURN)
		c:RegisterEffect(e1)
		local e2=e1:Clone()
		e2:SetCode(EFFECT_SET_BASE_DEFENSE)
		e2:SetValue(c:GetBaseDefense()/2)
		c:RegisterEffect(e2)
		local e3=e1:Clone()
		e3:SetCode(EFFECT_CHANGE_LEVEL)
		e3:SetValue(2)
		c:RegisterEffect(e3)
	end
end