Will the oppressive ruler, the unjust murderer, and the cuckold abide eternally in Hellfire?

The aforementioned matters are major sins. The belief of the Sunnis and the Community is that one who commits a major sin is not an infidel and will not abide eternally in Hellfire if they die upon monotheism, and their fate is subject to God's will.

As for the oppressive ruler, he may be forbidden from entering Paradise at first, and his entry may be delayed.

However, one who unjustly kills a Muslim soul will not abide eternally in Hellfire.

And the cuckold will not abide eternally in Hellfire, even though he has committed a grave sin.