Osman is a great commander for new players who do not have nuking legendary commanders especially for new servers in Rise Of Kingdoms. Osman Talent Tree is bad for field fights so you will usually use him as a secondary commander.
Baibars was the forth Sultan of Egypt and Syria during the Mamluk dynasty. In September 1260, he routed the invading Mongol army at the Battle of Ain Jalut – this was the first major defeat ever suffered by the Mongols. During the battle, Baibars implemented a strategy of hit-and-run tactics, which baited the Mongol forces into an devastating ambush. Baibars is renowned both for his victories against the Mongols and Crusaders, and for the administrative reforms he implemented within the sultanate. An ambitious military leader, Baibars organized an army and restructured the existing navy. He donated heavily to public works, including building roads, mosques, schools, and post offices, as well as irrigation projects to increase the country’s grain production. Baibars’ reign pushed the Crusader’s out of Mamluk territory once and for all, and began a new age of Mamluk supremacy in the Eastern Mediterranean.
Osman is a great commander for new kingdoms but later he will lose value. Why? A lot of people will get a nuking commander that can do an insane amount of damage like G.Khan and they will focus you. Osman does not have any defensive skills and you will die insanely fast. So that is why I would not recommend using him on old servers.
In the early stage of the game, you can use him for a rally to, he will prefer good.
From skills, you can see that he is all about nuking so pair him with a commander that will provide nuking and rage generation
When you are fighting on-field try not to get focused while using Osman or you will die fast.
Good Pairing options for Osman are:
He will bring some Survivability and rage generation. great pair for new kingdoms.
Also pair that will have nuking and rage generation. But be careful, you can die fast.