I haven't roleplayed on this wiki before, so forgive me if something like this is already in use, but what do you think about assigning characters a number to represent how powerful they are? More powerful characters would have higher numbers, less powerful characters would have lower numbers. For right now, let's call it Magic Power Level, or MPL for short. For reference, basing it off the recent blog post about character power classes, it could look something like this (keep in mind a character may have a specific MPL but not be in the class that MPL is generally tied to):
Mage: 1-999 MPL
S-Class Mage: 1,000-2,999 MPL
Jose Saint Class: 3,000-4,999 MPL
Makarov Saint Class: 5,000-6,999 MPL
Top Four Wizard Saint Class: 7,000-9,999 MPL
Spriggan 12 Class: 10,000-12,999 MPL
August/Irene Spriggan Class: 13,000-15,999 MPL
Acnologia/Five Dragon Gods/Fairy Heart Zeref Class: 16,000+ MPL
To state it once more, characters aren't necessarily in whatever group their MPL is generally tied to, it's just for reference so you have an idea how powerful a specific MPL is. Now that that's out of the way, I would also like to state I haven't read or watched the entirety of Fairy Tail, so any of these numbers could change; I picked them just to show how this MPL System might work.
Now what would these numbers be used for outside of directly comparing them to another wizard? Why, roleplay, of course! I'd imagine the number could be taken and then multiplied, divided, etc. to figure out how powerful a certain attack would be, or how much Magic Power a wizard has. Furthermore, there could be a system of strengths and weaknesses, so certain magics may be weaker against others -- e.g. Fire Magic against Water magic -- so Fire Magic may have, say, a -50% multiplier against the magics it's weak against. On top of that, there may be semi-weaknesses, such as Sand or Wind magic, which Fire Magic might have a -25% multiplier against.
So what's the end goal? Well, I'm not quite too knowledgeable on the roleplays on this wiki, but I've seen roleplays elsewhere without a set of guidelines such as these where people will just go "I hit you really hard with a giant ball of fire!!!" and the other person can go "Noooo I dodge it and then blast you with acid, melting you and killing you!!!!!" and so on and so forth. This sort of system of Magic Power Levels, strengths, weaknesses, and whatever other situational multiplier may come up can help make sure fights are fair. Of course, there would be dice-rolling or some other sort of RNG involved (much like a tabletop RPG) in order to keep things interesting and not have a fight be decided from the very beginning. Furthermore, smart moves could give the user positive multipliers as well, so it's not just mindless fighting.
What do you think? Is it a good idea? Am I an idiot? Is something like this already in play? I'd genuinely really like some feedback. I have more ideas for this, but just wanted to give a brief description so it's easy to digest.