Is Saddam Hussein considered a martyr based on the Hadith in Bukhari concerning the one who killed a hundred souls and repented? And can a tyrannical, murderous, oppressive ruler be a martyr if he repents and is killed, and what is the ruling on his previous crimes?

The mercy of Allah is vast, and no sin is too great for it, for He is wide in forgiveness. An example of this is that Allah forgave the one who killed a hundred souls due to the sincerity of his repentance. The term "martyr" (shahid) is originally applied to one who is killed while striving in the way of Allah to elevate His word.