Welcome to my AP Brand mid guide. I will teach you how to play Brand in the way that I think is best. After playing many games with him, I have figured out many of Brand's strength's and weaknesses. Although I am not a professional, I hope you take my advice into consideration.

Taking these masteries on Brand

You may be asking, what's the benefit of taking this setup? I will explain them in here.

Taking 18/12 Masteries: Brand is a high-damage AP carry mid laner. The best options for him will be damage, which is why you max out the Ferocity tree.

Taking Oppressor: Usually, people will tell you to take Bounty Hunter on Brand, but I have found Oppressor to be more effective. The reason that I have come to this conclusion is because when you do your E>Q>AA>W combo, the W will do extra damage from it's Blaze passive, and from Oppressor.

Taking Secret Stash: Secret Stash turns your normal health pots into Rejuvenation Biscuits. For AP champions, having these biscuits are a great help for the instant health give back, great health regeneration, and slight mana recovery.

Taking Meditation: Taking Meditation over Merciless is an interesting choice. Overall, I have found Meditation to be more helpful.

Ignite is a great summoner spell for mid-laners. For Brand, it is especially helpful for securing a kill. It has a 210 second or 3.5 minute cooldown. It deals 50 + (20 x level) true damage for five seconds, which is similar to his passive. With Brand's new three stacking passive, an enemy can be finished off by igniting him, and waiting for the Blaze passive to go off.

Flash is a required summoner spell for almost all champions. It has a 300 second, or 5 minute cooldown. It blinks you a maximum of 425 units away. It is necessary for Brand since he has no other escape ability.

Rylai's Crystal Scepter

Rylai's has always been a good first item for Brand. It pairs well with his Blaze passive, and provides a decent amount of health and ability power. This should always be in your build as Brand.

Liandry's Torment

Liandry's Torment is another item that pairs well with Brand's passive. Liandry's also provides more sustain, and a decent spike when heading towards mid/late game.

Sorcerer's Shoes

The best boots for almost every AP champion. Provides basic speed, and a decent amount of magic penetration, which is always necessary.

Rabadon's Deathcap

A huge powerspike for Brand. Rabadon's will drastically increase your ability power, and overall damage. Best item for heading into lategame.

Void Staff

Another great lategame item. Every AP champion should buy Void Staff. It's probably the best item for magic penetration, making it extremely useful for Brand.

Zhonya's Hourglass

The most common AP/Defensive option. Although it was nerfed, Zhonya's still provides a strong active and decent stats, especially if against a heavy AD team.

Luden's Echo

Luden's is another strong item when heading into lategame. Usually, this replaces Rabadon's if you think that it's more necessary to have its passive.

Athene's Unholy Grail

This is a less popular item (especially with the Abyssal buff), but it could be viable due to its mana regen. Buy this item if you feel that you need more mana regeneration and cooldown reduction than Abyssal Scepter would give.

Abyssal Scepter

A great AP/Magic Resist item, especially after its buff. Get this item if you are falling behind to another AP champion. Also provides a slight amount of indirect magic penetration

Blaze
After an ability connects with something, set them on fire.
Sets an enemy (minion, monster, champion, etc) on fire, dealing 2% of the target's health over 4 seconds. This can stack up to three times. On the third stack, an area around the target will be highlighted, and it will detonate shortly after it is reached. This detonation will deal damage to anybody standing in its area. Each ability has a different effect when used on an enemy with Blaze on them. Each has its own pros.
Sear
A linear skillshot which deals magic damage.
8/7.5/7/6.5/6 second cooldown at each level
Brand throws a fireball that can only hit one enemy at a time. If the target has been affected with Blaze, Sear will stun.
Pillar of Flame
A pillar-like skillshot which falls from the ground shortly after casting.
10/9.5/9/8.5/8 second cooldown at each level
When casted, a circle will be placed on the ground, and deals damage 0.625 seconds after casting. This high damage ability is great for poking behind minions. If the enemy is affected by Blaze, Pillar of Flame will deal 25% additional damage.
Conflagration
A single-target point and click ability which deals damage and sets the enemy on fire.
10/9/8/7/6 second cooldown at each level
A point and click ability which deals decent damage, and also applies Blaze. It is most effective when comboing (E>Q) because it ensures that the enemy will be hit with Blaze. If the enemy is affected by Blaze, Conflagration will spread to enemies nearby. It is also effective when farming due to its Blaze passive.
Pyroclasm
Brand's ultimate ability.
105/90/75 second cooldown at each level
Brand launches a fireball at a single target, which bounces off of enemies nearby up to four times. Extremely effective in teamfights. If the enemy is affected with Blaze, Pyroclasm will briefly slow all enemies hit. Pyroclasm's Blaze effect is basically useless once Rylai's is bought.

Farming with Brand is easy, and does not need too much explanation.

Before you hit level three, try to last hit minions. Brand's auto attack animation is not the worst, so it does not take much time to get used to. If minions are bunched up, use your W do inflict damage and apply Blaze's DOT.

Post level three, you should still last hit, but now you have your E, which proves to be effective when farming. The best way for Brand to clear waves is by casting your W on a group of minions, and then using his E on one of the minions affected by Blaze. This inflicts a good amount of damage, and applies a DOT. If your W is on cooldown, it is an option to Q one minion, and then E the same one.

Some champions that Brand has synergy with:

Jarvan IV is a very good champion to pick with Brand. A good Jarvan ult combined with a Brand ult can wipe out the whole team very easily.

Amumu is another great champion to pick with Brand. Like Jarvan, a good Amumu ult can lead into a Brand ult. This is easier to pull off than Jarvan, and is more effective because Amumu's ult stuns, making it so that enemy champions can't flash or dash out.

Sona is an okay pick when combined with a Brand. Although Sona isn't played very often, a very good ult can help Brand, although it is very hard to hit a five-man Sona ult. If you feel confident enough, this could prove to be an effective support pick.

Thanks for reading through my Brand guide. I hope it helped. Leave any suggestions in the comments.