First one is easy, just use your infernal attack to destroy those towers.
Second one... funny, coz you've to fight god. Run around and fire infernal attacks/shots at him. Train your rolling skills also, it'd be helpful in this boss fight. His attacks are.. I dunno how to describe, beautiful maybe. It's quite wide-area but weak damage, you should have no problem in defeating him.
Final Battle.. you've killed God, now you're facing Satan(WTF). It's really, really tough. Watch out, don't get close to him if you're close enough he'll use his Satan punch and kill you regardless to how many HP you've left. 1-Hit-KO. He'll use flame throwing attack usually, which deals 10-20 damage. Beware you have no infernal attack, so simply shoot him with everything you have. Once he crouch down and recover from your attacks, find a computer somewhere around with yellow light. Activate it and a path to the Ball will appear, now run upstairs, approach to it and activate the switch. Beware of Satan's attack and don't fall down while evading attacks. Get back and activate another computer and repeat the steps, the only difference is that you're going higher and higher. Once 3 switches are activated, the ball will explode and Satan will be down. Watch the ending, and you'll realise yourself saying "WTF" after watching the so-call ending.
Considering to write a detail Boss fight strategy guide... anyone wanna help?
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