Here's a guide for all the species in the RPG. I hope it helps!
Mystics- Mystics look very similar to humans. The only physical difference is that mystics have strangely colored hair (i.e green, bright red, silver). A mystic's hair color usually depends on their area of origin (i.e Forest Mystics will have greenish hair, Water Mystics will have blue and so on). Mystics are all gifted with magic from birth. Mystics' magic tends to be pretty strong depending on the individual and how much they use their powers. Mystics personalities vary however most are offended easily and some hold a very strong sense of self-worth. Most mystics can summon if they have trained enough in the magical arts. Mystics usually use magic and summoning to fight. Some mystics have weapons and most of the time the weapon is adorned with some type of magic.
Demons- Demons come in all shapes and sizes. They are also psychologically complex and hard to generalize in that area. Demons sometimes are mixed with other animals (i.e cat demons, bird demons, etc). Demons are most of the time born with magic. Demons have dark elemental attributes most of the time. Demons' fighting styles vary. Some use magic, some weapons, some both. Some demons can summon but do as they tend not to need to summon.
Advanced Humans- Advanced humans are exactly like humans as far as their minds and physical appearance. They are humans who have gone through biological upgrades and modifications. Advanced humans are physically stronger than normal humans. It is possible that their magic may also be stronger but this has not been proven. Advanced humans may be able to summon but it has never been seen done. Advanced humans only exist in the Future Age and the End Age.