Revenge with the Power of the Final Boss

"I just left an honest review, and I was reincarnated. But not into the novel I criticized—into the world of [SSS-Class National Power Heir]. I reincarnated as Baek Seo-jun, the older brother of the original protagonist, faced discrimination, and was discarded as a sacrifice. And then I experienced hell. With the power of the final boss, I will exact revenge on everyone—whether it's the original protagonist or the villains. [The protagonist who has gained the power of the final boss]