This mission begins with Nero encountering a new breed of lesser-demon: the Mephistos. To defeat them simply shoot at them until their "cloak" disappear. They are vulnerable after that (you can also use Charged Shot Level 3 to save time as well as to deal more damage if you have bought it at this time). After defeating them, destroy the statues of ice and tombstones to gain some red orbs. You can also find Secret Mission 3 below the staircase. This secret mission will be pretty hard to complete until you have beaten Angelo Credo and have acquired the Hold ability. So just simply head straight up the stairs and into the Master's Chamber.
Defeat all of the enemies here to gain access to the next area. You can also play Secret Mission 10 here, just located above the fireplace where you need to destroy the glass first.
Torture Chamber (top)Edit
Now in order for you to get out of here you must obtain the key item Wing Talisman but before that you must kill all the Mephistos here. After defeating them simply obtain the key item. The Jump Pads up there will activate (they will glow in red), and jump on top of them will take you back up. There are also items and red orb crystals so if you lack some, you can farm here. There is also a Holy Water, which is really helpful in sticky situations.
Collect all red orbs, jump onto the red magic platform and land on to the huge chandelier. Hit the post with Red Queen, and there will be a cutscene with Nero slashing the post, making the chandelier to swing towards Sanctus' portrait that hides a secret tunnel. Enter the tunnel.
Just follow the path until you reached a point and a cutscene will play showing Sanctus' resurrection and the end of the mission
- The mission title refers to an indulgence of 100 days is associated with the Trisagion when prayed once a day together with the Sanctus, with a contrite heart to adore the Holy Trinity.
- This is the only mission wherein two Secret Missions are found in consecutive areas, the Secret Mission 3 being on the Soldier's Graveyard, and the Secret Mission 10 in the Master's Chamber.