Below is a walkthrough on the main story quests in Chapter 6 of Atelier Ryza.
The Final Battle…!?: 1
Visit Ryza’s home, Rasen District, Boden District, Valentz residence in Old Town and Treppe Hill then return to the atelier. Afterwards, head to the Boundary Cathedral in Hidden Cove to trigger a cutscene. Enter through the gate then defeat the Cluster Beetle. With that complete, press through Ashen Forest to find Kilo.
The Final Battle…!?: 2
Keep heading further into Ashen Forest, passing the Lost Oren City and entering the Dark Abyss. In the very north of the Dark Abyss, you’ll come across the Ravaging Queen. Defeat her in battle. After the long, painstaking battle, return to the atelier.
Past the Present: 1
Travel to Kurken Bunker then return to the atelier to automatically unlock the Red Stone recipe. You will then need to synthesize a Red Stone with at least 120 Quality. Once you’ve synthesized it, return to Kurken Bunker to test it out. Since it failed, return to the atelier to synthesize a Crimson Stone, which can be unlocked using the Red Stone recipe. With the stone created, head back to the Kurken Bunker to test it out one more time!
Past the Present: 2
Next, it’s time to travel to Ashen Forest in the Underworld to trigger a cutscene. With Oren’s water restored, walk back to the gate and proceed through it to trigger a long cutscene. After sealing the gate, return to the atelier. Now it’s time to head to the Rasen District, Boden District, Kurken Port, Brunnen Mannor and Valentz residence. *NOTE: Not only do you need to fast travel to the Boden District for a cutscene, but you will also need to follow the objective to Lent’s house for another cutscene! Once you’ve visited all the places, return to the atelier for the final cutscene!