#bran speculation

"There are some who call my order the knights of the mind," Luwin replied. "You are a surpassing clever boy when you work at it, Bran. Have you ever thought that you might wear a maester's chain? There is no limit to what you might learn."

"I want to learn magic," Bran told him. "The crow promised that I would fly."

Maester Luwin sighed. "I can teach you history, healing, herblore. I can teach you the speech of ravens, and how to build a castle, and the way a sailor steers his ship by the stars. I can teach you to measure the days and mark the seasons, and at the Citadel in Oldtown they can teach you a thousand things more. But, Bran, no man can teach you magic." - Bran VI AGOT

Greenseers in a way are the Knights of the Old Gods.

Bran has already learnt to speak to ravens just not in the way Luwin intended but still. Same with history and measuring the days, Bran is just learning it in a different way by looking directly into the past.

Does this mean Bran will learn all of these things just in a different way than his Maester intended.

Like use weirwoods at different castles to learn how they were built so he can repair and build new castles/cities.

and her boy lying there broken, the sweetest of her children, the gentlest - Catelyn III AGOT

The Bastard himself was dead Bran learned that evening over supper. Ser Rodrik's men had caught him on Hornwood land doing something horrible (Bran wasn't quite sure what, but it seemed to be something you did without your clothes) and shot him down with arrows as he tried to ride away. They came too late for poor Lady Hornwood, though. After their wedding, the Bastard had locked her in a tower and neglected to feed her. Bran had heard men saying that when Ser Rodrik had smashed down the door he found her with her mouth all bloody and her fingers chewed off. - Bran V ACOK

"Some people hurt others just because they can," said Jojen.

"And it wasn't Theon who did the killing at Winterfell," said Meera. "Too many of the dead were ironmen." - Bran II ASOS

Bran has a gentle heart, but we know he's seen the vile things Ramsay has done through the heart tree.

Bran has already repressed what Jaime did but some of that anger is still there shown when he thinks about how he could "tear out the kingslayer's throat".

In Winds, we may see his gentle heart tested as we learn his thoughts about what Ramsay has done.

Seeing someone truly just torture and hurt people the way he does and enjoy it.

He has heard of it before with Lady Hornwood but to see it personally especially with what he's done with Theon and Jeyne who he's known his entire life, especially the later who has never harmed anyone.

Not to mention Beth, Old Nan, Palla, and the others being held in the dungeons, Bran yielded Winterfell to protect everyone only to see them being hunted like animals.

"If ice can burn," said Jojen in his solemn voice, "then love and hate can mate. Mountain or marsh, it makes no matter. The land is one." - Bran II ASOS

Once outside the godswood the cold descended on him like a ravening wolf and caught him in its teeth. He lowered his head into the wind and made for the Great Hall, hastening after the long line of candles and torches. Ice crunched beneath his boots, and a sudden gust pushed back his hood, as if a ghost had plucked at him with frozen fingers, hungry to gaze upon his face.

Bran's love for his people bringing out a hatred in him.

"The oak is the acorn, the acorn is the oak. And the weirwood … a thousand human years are a moment to a weirwood, and through such gates you and I may gaze into the past."

And now the lords Bran glimpsed were tall and hard, stern men in fur and chain mail. Some wore faces he remembered from the statues in the crypts, but they were gone before he could put a name to them. - Bran III ADWD

Bran will use this ability day and night to learn things he needs to know and quickly.

Learning more about battle strategy through seeing how King Rickard defeated the Marsh King, how Brandon Ice Eyes took back the wolf's den, how Willam and Artos defeated Raymun Redbeard.

How different castles have been sieged by using their heart trees like casterly rock, highgarden etc. How Harlon Stark sieged the Dreadfort.

Learning how to build and sail ships through watching Brandon the Shipwright, how Lords of the arbor maintained their fleet given the arbor likely has a weirwood too.