You're following Imam hanifa (persian) school of islam because turks in that time drunk horseblood, they did not know anything about religion and philosophy, copied some shaman rituals from mongols.
Who killed umar and why? this is also a separate debate which I'm not going to start (religious discussions are not allowed).
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "The Hour will not be established until you fight with the Turks; people with small eyes, red faces, and flat noses. Their faces will look like shields coated with leather. The Hour will not be established till you fight with people whose shoes are made of hair."