Lord Shen is Cobra's former apprentice and another of his favorite (next to Dark Cynder) but now with both reformed traitors, Cobra isn't left with alot of favorites with the consideration that Tai Lung was too much of a failure cause of simply being prevented by Oogway and sented to jail for a long time and a Big Bad of Kung Fu Panda 2.
Shen is (or was) also a major player in the Villain League due to his connections with Cobra and what became of the Radiant Garden. According to rumors, Shen himself was just a corrupted pawn of Cobra, (the as of now more true villain of the Radiant Garden disaster and the Panda Village slaughter), informed him that his parents lied to him about being destined to the throne, then said that he's just there for family appeal for his mother and father. Believed that he is un-loved, Shen asked if there's anyway for him to earn better respect and Cobra replied that he will have be his personal apprentice. Shen, not knowing any better, agreed to his terms and Cobra led him the dark ways of fireworks and, of course, resulted in the following story.
Cobra's main reason for letting Shen be corrupted because since he craving for power and domination, he would just let others follow his steps for the sake of it but the more true reason has yet to be explain but it's more likely something involving the aftermath of Cobra's own corruption from Malefor and that Cobra, like Cynder before him, had to go though an intension to be declared a dark leader of the leage and Shen was the target.
Even though His parents loved him and the people began to find joy in fireworks, Shen began to become obsessed with gaining their love due Cobra's witch craft and dark teachings then began thinking about making weapons with them. Frightened with their son's cause, his parents requested the Soothsayer of what his future awaits if he continues down the dark path. The Soothsayer revealed to them a vision of his defeat by a warrior of black and white. Overhearing this and fear for his plans, Shen lead his wolf followers to attack and decimate a nearby farming village, populated by giant pandas. When his crime was discovered, Shen was exiled by his own father from his home and his throne was turned over to Master Thundering Rhino and the Kung Fu Council.
Deep in the mountains, Shen's wolves worked tirelessly to complete their master's ultimate weapon but when the Wolf Boss informs him that they had run out of metal to use as material so he orders him to attack the farthest villages and steal all the metal they could find. While he and a group of wolves attended to that, Shen decided it was time to move forward with his plans.
He traveled to Gongmen City and marched up to his former home. Once there he confronted the Kung Fu Council, telling them he was there to take back what was his. In the skirmish that followed Shen easily out fought Master Storming Ox and Master Croc but was pushed back by Master Thundering Rhino, who shattered several of Shen's blades. Shen was prepared for this and unveiled his new weapon, a cannon. Thundering Rhino prepared for battle but was was no match for Shen's device and was killed. With Thundering Rhino dead Shen threatened to turn his cannon on the city unless Storming Ox and Croc surrendered. He had the two masters imprisoned in Gongmen Jail and planted Master Rhino's Cloud Hammer in his courtyard as a trophy.
With the Council out of the way Shen ransacked the Peacock Palace, even throwing his father's throne out the window and replacing it with his cannon. He then questioned the Soothsayer about his future but she informed him that nothing had changed, that he would be defeated by a warrior of black and white. He declared this to be impossible but is quickly proven wrong when the Wolf Boss returned and informed him that he had fought against a panda. Shen, greatly angered by this, ordered him to bring the panda to him so he could prove the Soothsayer wrong.
Later when Po and the Furious Five are brought before him in handcuffs, Shen taunted Po not only about his appearance but his ignorance about his past and Shen's role in it. He ordered the Wolf Boss to fire the cannon at them but Mantis quickly extinguished the fuse and knocks the wolf out. This bought Viper enough time to pick the lock on Tigress' cuffs. Once they were free, Tigress and Mantis destroyed Shen's cannon and Po tried to attack Shen. However, when he saw the marks on Shen's feathers he realized Shen was there the night he lost his biological parents. Shen used the distraction this caused to escape to the fireworks factory, where he had several more cannons waiting. He ordered his men to open fire and bring the tower down with Po and the Five inside. Despite this, they manage to escape. Frustrated, Shen ordered his troops to start loading his ships to begin his conquest of china.
Some time later Po infiltrated the factory to confront Shen, ruining the Five's plan to destroy the building. As the two fight, Shen easily outmaneuvering Po, he taunted Po again telling him he saw his parents abandon him and that they never loved him. This distracted Po enough for Shen to reach his most powerful cannon and blast Po out the factory into the river.
Confident Po was dead, Shen has the recaptured Furious Five chained up and suspended above his ships as they sailed out of the city. Much to his shock, Po returned and tried to rescue his friends and defeat Shen once and for all. Shen ordered his gunners to blast him but Po nimbly moved along the rooftops, preventing them from getting a clear shot, and then jumped onto the ships to engage Shen's army, now that they couldn't fire without hitting their own men. Shen could do nothing but watch as Po freed the Furious Five and joined forces with Masters Storming Ox, Croc and Shifu. Finally losing his patience, Shen ordered the Wolf Boss to fire the main cannon but he refused to kill his own men. In response to this Shen strikes him down with one of his throwing knives and fires the cannon himself, knocking all the kung fu warriors away and blasting through the boats they had set up to block his fleet.
As his ships entered the harbor Shen watched as Po swam out to one of the destroyed boats and began making Tai Chi motions. Unphased Shen ordered his gunners to open fire and finish the panda. Amazingly, Po used a technique Shifu had showed him earlier to catch and deflect the cannonballs, sending them back and destroying all of Shen's ships and cannons. When Po confronts him on his main ship Shen asks him how he did it, how he could find peace after what he did to him. Po tells him that it was time to let go of his past and choose his own future. Instead, Shen attacks Po with lance and knives. Shen's swordplay overwhelms Po but as they fight he accidentally cut through the ropes holding the remains of his cannon. He realized this too late and as the heavy weapon falls Shen closed his eyes, accepting his fate.
Shen is extremely smart, supremely lethal, and burns with ambition; it is a combustible combination. His past has forged in him the notion that he's been wronged and that the world owes him something. He intends to do everything in his power to take it, which includes inventing a powerful weapon unlike anything the world has ever seen. Shen is intent on using this weapon to wipe out Kung Fu and take over China. That puts him on a collision course with Po and the Five.
Shen is shown to be unspeakably ruthless, willing to decimate an entire village just because a simple fortune-telling warned him one of its inhabitants would be his downfall. Still, he shows some cowardice a few times in the movie, such as when he was willing to kill China's population of pandas (or at least the nearest village to Gongmen) in order to prevent the Soothsayer's prediction from comming true, and preferred to let his cannons and henchmen do his dirty work rather than dealing with his obstacles himself. He has no regard for any life but his own, as he blasted a bridge in his way without hesitation, despite there being villagers on it, and was willing to sacrifice his own troops, which put him in conflict with his most trusted subordinate, Boss Wolf, who refused to kill his own men, leading to Shen striking him down simply for his disobedience. Shen is rather sadistic, claiming to Po that his parents abandoned him and did not love him, taking advantage of the panda's pain, and enjoying the emotional scars he inflicted on Po. Saying Po's parents abandoned him may have been a result of Shen being jealous that Po's parents loved him while Shen's own parents, to him, did not love him, which is a primary reason to his taking a wicked path. Possibly, the only one Shen ever really loved was his childhood nanny, the Soothsayer, despite the threats and insults he gave her while she was his prisoner. But still, he remembered her love and kindness and set her free, claiming "She is of no further use to [him]."
Reformed, he is somewhat still hard headed (If occatinoinly hot-headed), somewhat non-callent most of the time, and rarly refers his fellow lougers by name, with only Boss Wolf and Cynder he addresses by name, give or take the five or Soothsayer, he has a tendingcy to refer the others based of their features, types, colors, race, etc. Like Cynder, he is personaly ashamed that he allowed himself to buy a single word Cobra said, even when he was the least bit secptical of Cobra's somehow convincing words, and is determen to "Make it right".
Even though Lord Shen is a skilled and accomplished Kung Fu master, he is more likely to use his cunning or his cannons than his physical prowess. He excels in sword combat and hides an armory of blades in his robes, which he can unleash in lightning speed. Among his arsenal is his lance, which he was seen practicing with the most. Shen also has a pair lethal-looking metal talons, which he uses as armor, weapons, and means to light the fuses of his cannons. In battle, his tail becomes another limb, which he can shape and use to attack, defend or as a deception tool. His "Funnel Cloud Attack" and "Feather Attack" are daunting and deadly. All in all, Shen's fighting style is both graceful and lethal. And shown to be enough to effortlessly overwhelm both Storming Ox and Croc, both reverred and full-fledged kung fu masters, and counter their each and every move flawlessly and lethally precise.
In keeping with his state as an albino, Shen wears a long, white robe with a picture of a peacock at the back of his robe (which matches his plumage) with a black belt. Underneath his robe is where he keeps his halberd and a large supply of throwing knives. To hide the burn scars on his feet, Shen wears metal talons that protect his feet and serve as formidable weapons. Shen also hides sharp metals in his outstanding feathers!