What is the ruling on dealing with an oppressive father who abuses his children psychologically and physically, and does not provide for them, knowing that a gentle approach is ineffective with him; rather, it increases his oppression towards a specific individual?

You are not sinful for hating your father, but you should ward off harm and injury from him through permissible means, such as speaking with him and admonishing him. You should leave the place when there is harm, while still maintaining kindness, goodness, and praying for him. Do not raise your voice at him or insult him. Repel his harm with the easiest means available, because his injustice towards you does not negate his right to dutifulness. You will be rewarded for your patience with him.