Alright let me start with the giant wallie. I have been studying for this moment lol. Brace your eyes @_@
As we all know the Sharingan comes from the mighty Uchiha clan. When an Uchiha first awakens his Sharingan he starts out with a single black tomoe in each eye, which will then become two tomoe, and then three tomoe. The Sharingan is one of the three doujutsus, and in my opinion the uniquest of them all, and literally it means the "Copy Wheel Eye". It's power level is determined by how many dots, or the so called tomoes, that are shown in the eye when activated; the maximum of these tomoes is 3. The main abilities of the sharingan are basically seeing the chakra flow, genjutsu related abilities (meaning that you can break out of genjutsu or cast yourself a powerful sharingan genjutsu), tracking and prediction abilities.
Now I mentioned the abilities of the Sharingan, let me break them down for you, sensei. First lets start with the tracking and prediction abilities. About the tracking, well in our RP and in the ninja world, the Sharingan has the ability to slow down the movements when you are looking at it, meaning that movements will happen a lot slower to you than they are in reality, which gives you higher reaction time when encountering fast movements. Of course, as a result of high speed tracking and high clarity of perception, the Sharingan is able to catch the slightest movement that's done by your opponent/target, thus making the Sharingan a great asset in close ranged fights. About the prediction abilities, the Sharingan is capable of predicting ninjutsu techniques that's done by your opponent according to a set of rules; just to clarify, one has to have clear vision of the opponent's handseal usage and second you need to already know the technique that he's using (this works for all cannon techniques once you master them of course). The Sharingan is also capable of predicting Taijutsu movements. Now finally onto the copying part of things. Well this particular part is not fully achieved in this RP, because the Sharingan is capable of copying any techniques the user witnesses and can use. Since in our RP there is no limitations basically we all know the basic five elements, meaning that you don't really need to copy your opponent's elemental ninjutsu technique when you know it yourself, do you? When it comes to custom technique, there was a rule, if I remember right, that they can't be copied.
Alright then, let's continue with me explaining about the second ability, the chakra flow. That's basically the most basic Sharingan ability and can see the chakra flow of anything that has chakra flowing in it, and by itself it gives each and every chakra flow a distinctive colour; what I want to say is that people's chakra colour vary when you see it with the Sharingan. The Sharingan has also the ability to differentiate between the basic five chakra natures, because each elemental chakra has a unique feature to it that makes it noticeable by the Sharingan: lets take fire, its chakra is extremely hot which affects the colour pattern, wind chakra is composed of very thin blades, lightning chakra vibrates rapidly, earth chakra is very dense, which affects the colour by making it denser, water chakra has a certain flow.
Now about the third and final ability of the Sharingan. Let me start by giving an example how genjutsu works with the chakra system. When genjutsu is used it interrupts the pattern of the chakra flow making the chakra flow irregular which leads the Sharingan to discovering when the genjutsu is being used on them. The Sharingan is capable of determining the genjutsu when it happens by watching the irregular chakra flow, as I've already mentioned, in addition to that, the Sharingan is capable of piercing through visual genjutsu. One of my favorite parts of the Sharingan is that you can cast genjutsu with it. The genjutsu casted with the Sharingan is extremely fast, but has a huge drawback, is not only does it need you to have a clear view and gazing directly into your opponent's eyes, but also it needs your opponent to be looking at your Sharingan eyes to work, that's the case of most Sharingan related genjutsus excluding some of them which should be clearly written in the technique's description, anyway for the eye contact based genjutsu short range fights are your best option if you want to use it, you only need one second or one moment with a mutual eye contact to cast your eye genjutsu. It's all about how you combine a genjutsu. You need to start out with something so you can follow it up correctly. It's best if you look at the genjutsu as a chest game, being two moves a head of your opponent can be a game changer, depending of course against who you are fighting.
Now finally there is the Mangekyou Sharingan and the Eternal Mangekyou Sharingan, of course they are really exceptional abilities for one to have, for which you have to be an exceptional sharingan user to achieve them. I think I don't need to mention what they do since our training is not about them. Basically they are forbidden techniques which give you special sets of techniques, for which you will later on in the battle pay because a forbidden techniques does not only damage your opponent but also damages the user of it.