The prophecy of the "Warrior in Black and White". While Po is certainly the more direct interpretation and fits the mold perfectly, there is yet another great warrior of black and white that could qualify as well, Shen himself. After all it was only after his attempt at genocide did he get exiled from his home. He also died from his own hand, rather intentional or not. And while Po did effectively destroy Shen's army, he sure had a lot of help from all those cannon balls that Shen kept sending his way. Even after seeing point blank that Po was actively throwing them right back at him.
What finally stuns Lord Shen at the end is notPo countering cannonfire with kung fu to singlehandedly destroy his fleet, but the fact that Po is neither permanently mired in a Heroic BSoD believing the lie that his parents abandoning him because they hated him, nor charging in a Roaring Rampage of Revenge for the extermination of his people.
When Po discovers what Lord Shen did to his parents, and for that matter species, his response is to... let go of his pain and find inner peace. Shen, who has never got over his own deep-rooted issues, is utterly shocked.
Played with when the Soothsayer and Shen first meet Po. They know that Shen attempted genocide against the Pandas, and assume that the reason that the Panda is here is to a) avenge his family/species, and b) destroy Shen once and for all. Both are shocked when they learn that not only had Po never heard of Lord Shen, but had no idea why he should have. The look on Shen's face when Po just brushes him off, totally ignoring the well-prepared speech upon their first meeting, is priceless.
Po's nightmare in the boat before the team's arrival in Gongmen. He reunites with his parents, only to find that they've replaced him with a radish which is quieter and better at kung fu than him. Said radish then proceeds to kick his ass.This sounds like a straight up version but it is less BLAM then it appears. Po is wrestling with issues of identity, where he came from, and his origins. The fear that his parents gave him up because they were trying to replace him or that they simply didn't want him is a very real fear of some adopted people, and his mind shows this quite clearly. He wishes to know why his parents gave him up, and why they wouldn't come back for him. The radish, though, was entirely BLAM, but it was a dream. The brain uses dreams to sort out bits and pieces of information that it gathers during waking hours, and since radishes played a large role in his father's tale, it's understandable that it would make it into the dream. Kung Fu is also a massive part of his life, so it would be incorporated in as well...
While trying to convince Masters Ox and Croc to escape the prison, Po delivers a Rousing Speech about how they will defeat Shen and destroy his weapon. A random prisoner then enthusiastically agrees, but he's never seen again. Oddly, he was a boar and had a completely unique character model. It turns out that this character was going to be in the movie as a fourth master (alongside Ox, Croc, and Rhino), but was cut for one reason or another and the character model was used in the place of a random criminal.
Contested Sequel: Opinion is pretty strongly divided - the first movie is generally regarded as having a stronger structure and a classic theme, while supporters of the second point to superior characterization and animation. That said, it seems more downplayed than most cases, since fans generally like both films.
Lord Shen. Any surprise? Driving the point home further, he tends to get the Bishōnen anthropomorphic treatment in fan art.
The Wolf Boss has also been subject to this. Despite his prominent role in the panda genocide, plundering of innocent villages, and direction of the goon squad that terrorizes Gongmen City, some people portray him as a cuddly puppy. He's a goofier character than Shen, but he's far from an Anti-Villain. Even him turning on Shen was a case of Even Evil Has Standards, not any remorse for what he's done under his command.
Ensemble Dark Horse: The Soothsayer. Much like Master Oogway in the first film, she's utterly beloved for being an incredibly wise, funny, and yet deeply human mentor figure, and her one-on-one scenes with Shen and Po are some of the best in the entire movie.
Evil Is Cool: Unsurprisingly, Lord Shen's many fans definitely think so.
Heartwarming in Hindsight: Li Shan fighting off the Wolf Boss to protect his son and wife is even more heroically badass when the third movie reveals that he has no knowledge of kung fu whatsoever... and went up against Shen's forces armed with nothing more than a father's love.
The part where all the kung fu masters have been wounded by Shen's cannon and Po swims over to Tigress who's floating on a wooden piece have many, usually Po/Tigress shippers, point out some similarities to Titanic. The funny part is when you remember that Po is voiced by a man named Jack.
They Wasted a Perfectly Good Character: Addressed by the writers themselves with the Soothsayer being voiced by Michelle Yeoh, a skilled martial artist, while her character is one of the very few never performing any martial arts in the film. They considered it justified seeing as the Soothsayer is an old lady, but still found it an ironic casting.