Literally just made my account today so this guide is probably scuffed. Hope you read it and not have a brain aneurism lol

Honestly, AP Rakan Mid at his best is slightly above average. He isn't broken, or sleeper, or OP. You need to get an early lead and play pretty well if you want to win mid to late game, otherwise you will just be a mediocre support with mediocre burst. But if you do play him well enough, he can surprisingly one shot squishies and some bruisers while also healing/shielding his team for an insane amount.

Electrocute should always be his main keystone. All of the other keystones don't work nearly as well as Electrocute does.

Sudden Impact synergizes with Rakan's W and E

Eyeball Collection is good for your scaling and your mid to late game

Ultimate Hunter is insanely good as your ultimate already has a kind of low cooldown

For the Sorcery runes, you can honestly change these to whatever you want or need. I like going Transcendence and Gathering Storm for the ability haste and extra AP

You should always bring flash and ignite. You don't need teleport as you already have high mobility and roaming, you don't need barrier since you have your passive shield, and you don't need exhaust since you have your R and W.

These are the items you buy at the start of the game.

Doran's Ring is good in general for any AP laner.

Health potions and a normal stealth ward are pretty obvious.

You usually buy these items on the first back.

Dark Seal is good for your roams since you will be racking up takedowns.

Boots are good for your roams.

Control Wards are good for controlling the river.

Pots are if you have a little more trouble trading with your laner.

If you don't have enough gold to buy both Dark Seal and boots, I suggest going for Dark Seal since you will be roaming a lot. The AP boost will help with your sustain since your Q can heal you up.

These are Rakan's core items, but if you really need to, you can switch them out to whatever you need.

Rocketbelt in my opinion is Rakan's best mythic for mid. Rocketbelt, while not having as much damage as Night Harvester, is better suited for Rakan since you actually have control over when you can dash making it great engage/escape tool. Other mythics such as Luden's are pretty good too, but Rakan needs the power spike as soon as possible, so the 200 gold difference is worth it.

Sorc shoes are obvious.

Mejai's is an incredibly powerful item to have, since you will be roaming and ganking a lot. The movement speed and AP will be incredibly useful too.

These items are for when you need to build against the enemy team.

Zhonya's is a really good source of armor, and it's active is one of the best in the game. You can use it to start engages early. You can R+W into the enemy team, Zhonya's to wait for a teammate to be in E distance, and then dash back to your team.

Banshee's is good for when the enemy team has a lot of AP. The Spellshield is also really useful for enemy champs who can burst you or if they have a lot of CC.

Morello is good if the enemy team has self-healers such as Aatrox, Katarina, or Sylas.

These are usually your second to last items or your build and are mainly just AP boosts

Rabadon's should 99% of the time be in your build. The amount of AP it gives is insane, and your passive, Q, and E all greatly benefit from how much AP you have.

Cosmic Drive is an overall good item. It gives you good AP, health, and movement speed. Rakan already has a high amount of health for a non-tank, so this item should help you become more tankier in your team fights.

I haven't used Horizon Focus that often, but you can use it with your Q. You need to start your fights with Q if you want to get the most out of this item, but it is still an ok item to use.

Lich Bane is good if you like weaving in auto attacks into your skirmishes. The passive deals a good amount of damage, and the movement speed is good too.

When the game starts, I like to hold onto my first point while clearing the first wave of minions. If nothing happens or if I see an opportunity to proc Electrocute, I put a point in W. If I keep getting poked, I put the point into Q. Otherwise, I max W, then Q, then E.

Rakan's abilities surprisingly scale well with AP. His passive scaled with 90% of his AP, so by late game you will basically be a full-fledged bruiser/tank. His Q damage scales with only 60% of his AP, but the important part is that his Q heal scales with 70% of his AP. This is really useful for trading, healing off of Drag/Rift/Baron while in the river, taking Drag/Rift/Baron with your team, and team fights where your team is bunched up and you can heal them all every 5 seconds. His E scales with 80% of his AP, basically letting you dash twice and giving an 800 shield twice to your team.

AP Rakan Mid is kind of niche, and will most likely not do very well against most mid laners. By fully understanding what he does though, you can be an incredible annoyance to the enemy team by dancing in-between them, CC-ing them, and being untargetable. You can do suprising amounts of burst damage in all stages of the game, and even if your damage falls off a little late game, you will still be able to shield/heal your team for a crazy amount. Hopefully this guide helps you a little in becoming the best Battle-Dancer you can be.