In Bleach, the souls of the dead can end up in one of several places. This determines their quality of life and ultimate fate. Dead souls will ideally be at peace as Pluses, and can then be escorted to the Soul Society without fuss. But a tormented soul will mutate into a Hollow, a cursed and ravenous being with no hope of salvation or peace. Baraggan Louisenbairn is the ultimate expression of that fate.
Despite being introduced earlier, Baraggan's big moment to shine came in the Fake Karakura Town arc, ranking as the 2nd Espada serving under Sosuke Aizen. Baraggan is not just a powerful Arrancar, though. He was once the king of Hueco Mundo, dethroned by Aizen himself. But no one should pity him.
Baraggan's Futile Quest In Hueco Mundo
Baraggan Louisenbairn does seem sympathetic at first, and the same might be true of Grimmjow Jaegerjaques. Both characters sought salvation through power, hoping they could escape the fear and futility of a Hollow's life by becoming the ultimate predator. In Grimmjow's case, he followed his instincts and gathered a squad of Gillian minions, while Baraggan really aimed high. He was a Vasto Lorde, the greatest class of Menos Grande, and his incredible strength allowed him to easily kill any Hollow that challenged him. Baraggan eventually became Hueco Mundo's de facto king.
In this sense, Barragan "won" the dog-eat-dog game of survival, and had nearly all of Hueco Mundo's Hollows united under him as an army while he sat on a throne. Intelligent Hollows such as Baraggan, Grimmjow and others knew their monstrous race had no real means of salvation or peace, instead doomed to a life of violence and war, so Baraggan tried to beat the system at its own game. No one can blame him for resenting the cursed fate of all Hollows, but this does not make him a noble figure in the quest to escape that fate. In the end, he had the heart of a villain after all, even when compared to other Menos.
Baraggan Owning His Villainy As A Hollow King
In light of all this, why isn't Baraggan a sympathetic anti-hero? It's true that he's a tragic being, like other intelligent Hollows and Arrancars, but the deciding factors are his personality, actions and goals, not just his circumstances. Baraggan's backstory and behavior in the present day make it clear that he was really just a monster all along, vainly trying to master death and lord his power over everyone else.
Baraggan did not seek to make Hueco Mundo a safer and happier place for other Hollows, regardless of whether that's possible or not. He never even attempted altruism or benevolence. Instead he made everything about himself, from escaping the fear of death to becoming a glorious king for everyone to worship. He sought great power, but kept it all to himself -- only villains are so self-centered and greedy.
Grimmjow follows a similar arc, wanting to become strong only for his own sake, even if he must devour every other Hollow in the world to reach his goal. Baraggan did bring peace to Hueco Mundo by uniting its population in his army, but only for his own sake. He wanted physical and political power and got it, but when he did, he felt empty once again. Baraggan even toyed with the idea of pitting the two halves of his army against each other merely for his own entertainment, truly the mark of a villain. Only Sosuke Aizen's arrival prevented that from happening.
By contrast, a fellow Vasto Lorde named Tier Halibel used her power to protect her three Fracciones, seeing them as foster sisters who needed her help. When Mila Rose, Emilou Apacci and Sung-Sun fell to Toshiro Hitsugaya, Halibel swore to avenge them. Nothing Halibel did was for her own sake, even when she succeeded Aizen and Baraggan as Hueco Mundo's ruler.
Baraggan retained all his arrogance as a fallen king, treating his six Fracciones like peasants and demanding their utmost loyalty. He showed no remorse at all when they fell in battle, merely cursing at them. When his own power was turned against him, Baraggan's lone regret was his failure to get revenge on Sosuke Aizen. Even in his dying moments, everything was about him.