[@Masaki Haruna] The whole story will be about exploring a place called The Wastelands. A place that was destroyed in the Mage War. Someone fled to that place and our characters will be sent to find him/her/hir. 
This place is different from the other places in the kingdom. Experiments roam the land free and technology there is more advanced than the rest of the lands. Because of the magic ban , many inventions were considered "taboo" so they are not used.  The action of the RP takes place 100 years after the war and many things about the war itself was forgotten or have become a myth. So there will be a lot of amazement from our characters when they see some of the inventions of the past.

About the magic. Every race available will have an a different magic type and costs of the use of that magic. 
Example : A dark human ( I'll explain each race in the OCC ) will only be allowed to master Black Magic and the cost of it will be probably life force. Their own or the others. They can learn other types of magic but will only be able to cast basic spells. 
Only the masters of old could use any kind of magic and casts the most complex spells that would need mastery of more than one magic type. 
For the spells themselves I will allow the players to choose only 1 complex spell ( only if explained how they've learned it because magic tomes and such were destroyed after the war and as I said. Magic is highly reglemented by the Warrior Guild. Now called the Empire ) and 2/3 basic spells. More magic spells will be learned after they start the journey. 

Another thing. All mages ( of any race ) live in this Citadel. A place where all mages are put to work for the Empire and are experimented on. So..the mage characters will know each other. They are not friends but they are acquatences. 

Sorry for any grammar mistakes I might've made. I am writing on the phone and it's hard to write using it.

If you have any other questions. Please ask :)