fix Dark Artist (#676)

c72520073.lua

@@ -2,26 +2,19 @@
 function c72520073.initial_effect(c)
 	--defdown
 	local e1=Effect.CreateEffect(c)
-	e1:SetDescription(aux.Stringid(72520073,0))
-	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
-	e1:SetCode(EVENT_BATTLE_START)
+	e1:SetType(EFFECT_TYPE_SINGLE)
+	e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
+	e1:SetCode(EFFECT_SET_DEFENSE_FINAL)
+	e1:SetRange(LOCATION_MZONE)
 	e1:SetCondition(c72520073.defcon)
-	e1:SetOperation(c72520073.defop)
+	e1:SetValue(c72520073.defval)
 	c:RegisterEffect(e1)
 end
-function c72520073.defcon(e,tp,eg,ep,ev,re,r,rp)
+function c72520073.defcon(e)
 	local c=e:GetHandler()
 	local bc=c:GetBattleTarget()
-	return c==Duel.GetAttackTarget() and bc:IsAttribute(ATTRIBUTE_LIGHT)
+	return Duel.GetCurrentPhase()==PHASE_DAMAGE_CAL and c==Duel.GetAttackTarget() and bc:IsAttribute(ATTRIBUTE_LIGHT)
 end
-function c72520073.defop(e,tp,eg,ep,ev,re,r,rp)
-	local c=e:GetHandler()
-	if c:IsRelateToEffect(e) and c:IsFaceup() then
-		local e1=Effect.CreateEffect(c)
-		e1:SetType(EFFECT_TYPE_SINGLE)
-		e1:SetCode(EFFECT_SET_DEFENSE)
-		e1:SetValue(c:GetDefense()/2)
-		e1:SetReset(RESET_EVENT+0x1fe0000+RESET_PHASE+PHASE_DAMAGE)
-		c:RegisterEffect(e1)
-	end
+function c72520073.defval(e,c)
+	return math.ceil(e:GetHandler():GetDefense()/2)
 end