When the game resumes, a clock starts counting down. You have five minutes to get out of the Underworld and off the island! Use your Devil Trigger liberally to increase your running speed and defeat enemies faster. Run out of Mundus's throne room, get out of the heart chamber, and in the circular room there is a Frost. You don't have to kill it, so bypass it for now if you think you'll need the time.
In the room where you fought Nightmare, there are a couple of Nobodies. Kill them to unlock the doors and move forward. The next room has another Frost in it, but you can run past it. Run down the hallway to the red glowing thing that will take you back to the mirror cathedral.
From the mirror cathedral, run around the hole in the floor and jump on the floating platform to go back to the regular cathedral. Now starts the real mission!
The timer will resume counting down from however long you had left at the end of the mission lead-in. In the Cathedral, there are some Marionettes laying around. You can bypass these as well if you're short on time.
Run down the hallway towards the far end. There are two Beelzebubs here that must be killed in order to unlock the Sealed Door. Head through it and into the airplane hangar.
As you step into the hangar, a cutscene will occur in which the floor will collapse and dump Dante in the canal system. Here, Mundus makes his last stand!
Mundus:The gate has been opened. Dante, you're not getting away. This is where you will die.
Dante: I'm not going anywhere. Besides, there's no place to go. Look around! This will be your burial ground as well.
Compared to the last mission, this one is a breeze, but don't let your guard down, either. Attack and jump to dodge his eye lasers. His health falls relatively fast. If Dante's Devil Trigger gauge can handle it, activating Alastor's Air Raid and making good use of Vortex should be able to quickly damage Mundus. After dealing enough damage to Mundus, another cutscene will happen, where Dante suddenly looks as though he's losing. Then, who appears but Trish! She's here to help Dante destroy her former master, and she loans him her lightning power!
At this point, stay back from Mundus and use your firearms to charge your Devil Trigger. He has those stringy worm-things growing out of him now that will snag and damage you if you get close. Once you have three runes filled up, activate Devil Trigger and fire at him again for the win!
A note to keep in mind about the final boss is that time is working against the player here. If the battle takes too long before one side loses, Dante will be instantly killed, no matter how high his Vitality is.
Walkthrough Part 2Edit
Just because Mundus is defeated doesn't mean Dante is out of the woods yet. Watch the cutscene, and get ready for another rail shooter mini-game.
You must navigate the caves underneath Mallet Island. Dodge the stalagmites and stalagtites as much as you can, and shoot the ones in your way with your ranged attack. If you run into something, your health with drop a little, but fortunately, you start this with full health.
Once you successfully escape, you're home free! Watch the cutscene and give yourself a well-earned pat on the back!
You've beaten the game!