I ment specifically Relic, empyrean never had any limit and neither did mythic (outside prequests)

As far as prior trials that is correct, again this apply to only the 99 trial as it unlock the weapons true potential (On the assumption Afterglow is done in the same method as 99 only more) Mythic involves the strongest current ToAU enemy, Empyrean involves the strongest creatures of the Void. (A place on the other side of Atomos just like Abyssea)