CrossCode

Story related Achievement, cannot be missed again. After finishing Chapter 5, Meet your party members and Go to Autumn's Fall - Ancient Center. Begin your story mission by interacting with the statue. To obtain the Green Seed Shade, you must defeat Hologram Frobbit. Follow the rabbit's path closely and you'll finally reach him on some Ruins. Attack him with the opposite color of him. (Like, If it is blue/cold, then attack him with fire, and if he turned heat/yellow, then switch to cold element and attack him)
Once you defeat him, you'll get the "The Trickster" achievement for defeating Hologram Frobbit!

Then return to the Ancient Center to collect the Green Seed Shade.
You can now join with your team to start the raid, so head over to the First Scholars HQ in Autumn's Rise to start. after a short briefing in the First Scholars HQ, your friends will log off, and you'll get the Dream sequence again! (Chapter is not finished yet) after logging in again. Meet your friends near the statue in Ancient Center again. Before starting the quest, make sure you have enough consumables, gears, and leveled up to match the quest's difficulty because there will be a lot of fights coming up.
Enter into the cave on the Ancient Center, which is on the left side from the Statue.
You can explore and grab chests but follow the route that goes in further left to exit out of the cave on another end.
You'll reach "Para Island", talk to Hlin and start the Raid Event. There will be waves of enemies and move forward. finally, you'll reach a portal for the final fight!

You'll get the achievement for completing Chapter 6!