This is my first attempt at a build guide, and i did it on ap sona mid, which is one of my favourite midlaners to play.

The runes there are chosen more as a personal preferance just because i like to do early trades and the armor and ap helps with that (also the mr if you're vrsing an ap midlaner). Also her early dmg is quite weak so this helps with that

The items i use are used because of the following reasons, Lich bane is really good on sona cause of the double aa empower you'll get with your q and passive. The magic pen. boots are a good choice just so you can damage tanks, same with the void staff. The lich bane because it is great on sona for the empowered aa plus lich bane plus passive plus ludens proc does tons of damage. Zhonyas is an exchangable item just because you might instead need more mr rather than armor, or dont need the passive because you aren't dying too much anyway, and ofcourse you get rabadons just so you do a whole lot of damage with your 600+ ap (depending on what you decided to build), if you want more ap and are really confident early on you can ofcourse get a mejais, or a rod of ages.

I have flash on sona because it is better to have than ghost because she pretty much has a free ghost. The same sort of thing goes for heal and barrier, i have ignite instead of those because she has a decent heal and a small sheid anyways. You could take cleanse if you are againt someone like twisted fate, but otherwise i wouldnt recommend it.

DO NOT PLAY THIS IN RANKED. Unless you get really good at it...

Pros with this pick are, you have great poke (especially once you get sheen), and you have great sustain, and decent kiting with your e. She is in general just good as a mid laner. However, the cons are things like, if you get all in'd pre lvl 6, you're probably going to die to a zed or yasuo or leblanc. and if you are vsing a zed or even talon, or just someone whose jump ability puts them BEHIND you, make sure you yous yourult behind you, where they will show up. also she hasn't got great escape unless yu get a few point into your e, so she is pretty open to ganks.

Once it gets to mid/late game and alot of teamfights start happening, she is phenominal, here's why. Since she is mainly supposed to be a support, she is great because when your team needs to do damage at the start of the teamfight, she uses q to increase people's damage, and when everyone's getting low, you can use w to heal your team, and then once you need to catch stragglers or run away, you have your e and your ult for doing so.

Playing sona mid is quite hard when it comes to cs'ing, just because her aa's are quite slow and she has really low base ad, so you are'nt doing much damage to minions early on. However, once you get your sheen, cs'ing becomes quite abit less tedious, it becomes quite abit easier.

All in all, i believe that Ap mid sona is really good, and in my own personal experience, i have beaten tonnes of enemies from zeds to yasuos to even some leblancs. If you are reading this, i really recommend that you try it, and if you do, dont be afraid to change up the build, or runes/masteries or even the way you play it to fit your personal playstyle. However, when i play it, just so you know, i generally sit back until i get my sheen, then i start to poke them down really hard with my q, and i generally also stack the passive until it will proc on my q so it does the most damage.