Ok I've asked a ton of people with the same response from all of them.
Ugg. Pendants latent only works with MP<51%. I see that the pendant latent works in merit point calculations. It also works when using a job with 0 mp cor/nin for instance. I have 4MP merits, so i always have 40 mp.
So will Ugg. Pendant latent work with my merits? Or will it count against it seeing this as 100% MP. Nobody has seemed to put a definitive answer on this so maybe somebody can tell me this so i dont waste my time with this item.