Simply put, it wouldn't be a Devil May Cry game without these iconic traditions making an appearance in one way or another.
Go through the doorway with four glowing orbs above it, followed by the doorway ... appear after the first wave of enemies, so you may need a stashed Vital Star S to pass this if you get too ...
Change into Devil Trigger and press X to fly. Grab the Red Orbs on your way to the green doorway above. This will end the mission. Mission 3 This mission puts you back outside. As you run forward ...