Search the Fortuna Castle
Second Mining Area
You are in the mines again. Run along the corridors and at the crossroads turn left. Destroy the wall and Red Orb Statue behind it. When you reach a lake go up using Grim Grips. There are two Blue Orbs Fragments. Reaching them is not an easy task. The first one is above the entrance to the corridor. You need to jump onto the platform on the left then up. You should see a few Grim Grips. To grab the lowest one, you need to jump right and then Kick Jump. Grab the rest of the Grim Grips - at the last one turn left analog stick to the left. The second one is on the other side of the hall in front of the entrance to the corridor. To get it you need to jump over the gap - it's rather wide and the whole action is VERY hard to do with Nero, so consider getting Dante to do the job. After that, you will need to fight the Scarecrows. Before you leave this area, take Vital Star S (break the wall near exit).
Fortuna Castle Gate
Take a Red Orb from the cliff on the right. In this area you will meet new enemies - Frosts. They aren't very hard to destroy, but you can't launch them into the air - grab them instead. There are some Green Orbs in the poles.
Grand Hall/Large Hall/Dining Room
In the hall destroy all chairs, benches and everything you can break to get Red Orbs. Go east to the Large Hall and take first door on the right. In Dining Room destroy what you can, take Orbs, leave and go along the corridor to reach Torture Chamber.
Destroy enemies and go upstairs. Now you need to use moving Grim Grips - it is very easy, just be careful to not fall (you will need to fight again to move forward).
Grand Hall/Central Courtyard
You can go in only one direction, so when you reach the door, enter inside. You will be attacked by Frosts, so clean this area and go to the Foris Falls. You should find Vital Star S on your way (above the pole in the center - use Kick Jump to reach it). Go back through the door to the east and enter the Grand Hall (through Central Courtyard). Activate the blue glowing machine with your sword and the barrier will disappear. Behind the mirror on the east you will find Blue Orb Fragment. Take a door on the east to reach a Gallery. Destroy everything you can and enter Library. You'll meet knights - Bianco Angels. They have shields (destroyable) but you can also jump over them and attack or launch them into air. After the fight take Anima Mercury and leave this place.