Mission 8 in Dmc Devil May Cry is all about searching and hunting for lost things: Dante will have to recover Phineas’ eye to keep going in his his mission and in the mean time he can also go on the usual little hunt for lost soul, keys and secret missions doors. If you wanto to obtain the SSS rank in all mission, getting all collectibles is one of the most important requirements since a 100% completion rate will boost your score at the end of the mission: still, you’ll need a solid performance in combat and completion time so no reason to get lazy just because you have found everything there is in a single mission.
Lost Soul 1: At the beginning of the mission, inside the tunnel, look up to your right and you will see a blue door which can only be opened by Angelic Weapons: if you are lucky you can open it by using the Osyris but with the Aquile the task will be a lot easier. Once opened, get inside the new area and grab the lost soul.
Lost Soul 2: As soon as the tunnel starts, get on the left the moment it becomes bigger the first time: the lost soul is right on the wall there.
Lost Soul 3: After the first Divinity Statue, keep going down the tunnel until you reach an opening: get inside the opening to get an easy lost soul.
Lost Soul 4 and 5: Once in the area infested with Harpys, the one with the destroyable floor, look around you to find three paths. Use the grapple to enter the areas labeled as platform 1 and platform 2 to get the two lost souls
Argent Key: One you are done with the enemies in the area where the train appears above you, get to the far end and then right: through a blue door openable with Angelic weapons you will find an Argent Key.
Copper Door: The Copper Door is close to Lost Soul 1, the one behind the blue door which need the Aquila or the Osyris to open up.
Argent Door: After the first Divinity Statue, keep going until you see a red door on the right: open it with the Arbiter and you will find the Argent Door right behind it.