Board Thread:Question and Answer/@comment-24596086-20150324191911/@comment-887715-20150403171502

To some skills, yup(like the 200% ATK buff skill, for example, they only increase from 10% to 15%). But the small proc chance increase does make a little difference indeed(especially if you're not using a skill unleasher in your team). Typically, you would want to invest the medals on which cards you're be using a lot. There's a Alliance Job that reduce the amount of medals used on skill upgrading, though, but then again, it's only by a small margin....