In the first area, Altairs will occasionaly drop Flea Men that you need to avoid while fighting a variety of enemies including a Skeleton Beast. The next room has a save room to the bottom right and the Sapiens Fio glyph to the top left. You can jump off an Altair to reach the glyph or you can come back later with other glyphs to help you get to the platform.
Gravedorcus primarily stays underground and uses its fin to attack you. It also spits out poison breath and spores. You can stand on the platforms to avoid his attacks. When the platforms are broken, it will charge towards you and jump. When it hits the wall, it will be vulnerable for few seconds to attack before it burrows. It is weak to ice and strike attacks.
In the next area at the bottom left is breakable wall containing a Diamond. There is also a Chamomile at the top right platform. At the end of the map is a church where you will encounter Albus. You can use the Sketchbook here to fufill the quest, Tragic Memories. At the bottom of the wall is a hidden Hermit Ring. Go back to Ecclesia and talk to Barlowe.