The CEO. The unfair treatment among others as well as the language used is terrible. On top of that, the manipulation and the game of pitting one colleague against another is an awful way to meet goals, and you wouldn't really realize it until you leave the company.
Over time I notice that while the CEO emphasizes about helping more people, he fails to even be charitable in his own backyard. Loyal employees who have been there for years have rarely been appreciated or promoted, or even be given a fair salary, with many others being severely underpaid. There is clear favoritism in the company where people are not fairly appreciated
Plus, the way he treats his PA is so appalling, I've seen some of them break down in tears because of the workload and the way they were being treated.