Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 8 monsters Gains 100 ATK and DEF for each monster in the GYs. Once per turn: You can detach 1 material from this card; until the end of your opponent's next turn, this card cannot be destroyed by card effects, also neither player can Special Summon monsters from the GYs.
--Ｎｏ．６８ 魔天牢サンダルフォン
--Number 68: Sanaphond the Sky Prison
local s,id=GetID()
function s.initial_effect(c)
	--Must be properly summoned before reviving
	c:EnableReviveLimit()
	--Xyz summon procedure
	Xyz.AddProcedure(c,nil,8,2)
	--Gains 100 ATK/DEF per monster in the GYs
	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:SetValue(s.value)
	c:RegisterEffect(e1)
	local e2=e1:Clone()
	e2:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e2)
	--Make itself unable to be destroyed by card effect, also prevent special summon from GYs
	local e3=Effect.CreateEffect(c)
	e3:SetDescription(aux.Stringid(id,0))
	e3:SetType(EFFECT_TYPE_IGNITION)
	e3:SetRange(LOCATION_MZONE)
	e3:SetCountLimit(1)
	e3:SetCost(Cost.DetachFromSelf(1))
	e3:SetOperation(s.operation)
	c:RegisterEffect(e3)
end
s.xyz_number=68
function s.value(e,c)
	return Duel.GetMatchingGroupCount(Card.IsMonster,0,LOCATION_GRAVE,LOCATION_GRAVE,nil)*100
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsFaceup() and c:IsRelateToEffect(e) then
		--Cannot be destroyed by card effects
		local e1=Effect.CreateEffect(c)
		e1:SetDescription(3001)
		e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE+EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_CLIENT_HINT)
		e1:SetRange(LOCATION_MZONE)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
		e1:SetValue(1)
		e1:SetReset(RESETS_STANDARD_PHASE_END|RESET_OPPO_TURN)
		c:RegisterEffect(e1)
	end
	--Neither player can special summon from the GYs
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_CANNOT_SPECIAL_SUMMON)
	e2:SetProperty(EFFECT_FLAG_PLAYER_TARGET+EFFECT_FLAG_CLIENT_HINT)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetTargetRange(1,1)
	e2:SetTarget(s.splimit)
	e2:SetReset(RESET_PHASE|PHASE_END|RESET_OPPO_TURN)
	Duel.RegisterEffect(e2,tp)
end
function s.splimit(e,c)
	return c:IsLocation(LOCATION_GRAVE)
end