WARNING: The following contains spoilers for BNA: Brand New Animal, now streaming on Netflix.
Netflix's BNA: Brand New Animal doesn't appear to have a main villain at first, focusing on general discrimination and xenophobia in society between the beastmen and humans. The beastmen moved into Anima City so they could live in peace, but Alan, the Head of Sylvasta Pharmaceuticals and a financier of the city, seems to have ulterior motives.
In the last few episodes of the series, he's confirmed as a dangerous mastermind and someone who, while he wants beastmen extinct, has a powerful connection to the species that goes back a thousand years.
Alan's studying Michiru and Nazuna, two young girls who got a blood transfusion with beastman DNA by accident. They turned into beastmen, though unlike other beastman it's difficult from them to disguise themselves as humans. When Michiru and her vigilante handler, Shirou aka Silver Wolf, track Alan down following shady clues,, it's revealed he wanted to collect all the beastmen in Anima City so he could test out a new product.
This is connected to his past: he's actually a pureblood beastman, a three-headed flaming yellow wolf. Even Shirou's Silver Wolf is no match against him. When Michiru and Shirou ask why he's doing this to his own kind, Alan makes it clear he believes the diluted beastmen and half-breeds such as Shirou aren't noble blood and are a disgrace to the species. There are only a few families like his existing and Alan wants to keep it that way. He particularly hates Shirou, the survivor of a genocide perpetrated by Alan's ancestor Raymond Sylvasta. All this time, Alan was using Michiru and Nazuna's blood to engineer a cure that could permanently turn beastmen into humans.
Alan brought the in cult known as the Silver Wolf Order, getting the beastmen emotionally attached so that when he'd expose their guru Nazuna as a fraud, the feelings of stress and betrayal felt by the beastmen would trigger Nirvasyl Syndrome. This makes them go berserk and turn into giant monsters, attacking each other; Alan claims this caused the civil war that wiped out Shirou's home centuries ago. Alan sees this killer mode as a sign of weakness, so his family's spent centuries and fortunes trying to commit mass genocide discretely. He even had the blood of a thousand pureblood Beastmen poured into him to power up, putting him on even footing with Shirou in battle.
Alan simply believes only the pure bloodlines will survive, and wants to use Nirvasyl Syndrome as an excuse to kill mixed breed beastmen. At a concert where Nazuna's to be exposed, the live broadcast will show the Beastmen ripping each other up as part of a "demonstration," thus allowing Alan's drones to shoot them up with the cure. Once the rampages are over, when governments see that beastmen can be turned into docile humans, Alan's company will make a mint as he's patented the cure. Most of all, he'll achieve his dream of taking out the bloodlines he deems unworthy such as Shirou's, because at the end of the day, he's all about classism and elitism. To the Sylvasta family, mixed breeds shouldn't exist, and it's an added benefit if they can profit off of the extermination process.
BNA: Brand New Animal is now streaming on Netflix.