You can obtain more Glyphs from the Glyph Dungeon and those are small stones which will boost a certain stat. You can equip the one that you want, so make sure that you equip the right one depending on what stats you will get the use of the most. For example, as a Mage I went for ATK and some HP because those are the stones which I had the highest quality and they are also some good stats overall. So try to upgrade the Glyphs that you get and also equip the best ones always.