Brand doesn't want or scale well with any of the mana items

Where do you think we are?

this is Riot games.

Brand, Anivia, Viktor, Nami, Soraka, Bard, Swain, Cass, and Xerath all could make excellent use of a few mana potions early on. "Just manage ur mana" Is not an appropriate response when the enemy can simply use their spell more and overpower them, and mana potions were the answer to the question of using mana to defend themselves against frequent aggression. What if the jungler takes the blue buffs for himself? What if your opponent uses energy/rage/cooldowns only? It's always been an issue that some champs HAD to build mana before damage, but now that choice cuts deeper for no apparent reward.