User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-28564135-20141015184114/@comment-26074976-20141015195240

Seeing as those skills are g-rank and most likely from the "best of the best" armours from Dara-Sub for example. They may not have many slots as they'll have other skills too. So the few a slots they possess you might need a really good talisman to gain another skill(s).