You unlock the mission "The Forge" after completing the mission "Rajivari's Legacy"
Open your mission log:
The Forge
Master Rajivari's ghost told you that Nalen Raloch has been driven mad by power. Nalen wants to destroy the Jedi Order, starting with the ancient Forge where lightsabers are made. Rajivari has told you to recover a crystal from the Forge entrance to use with the first blade's hilt, to create a new lightsaber.
Your first task in this mission is to gather a Lightsaber Crystal. Exit the Ruined Acropolis into the Forge Remnants and head south towards the Forge. Inside the caverns, kill 12 Cavern Horranths for the bonus mission "Crystal Cavern Cleansing". Harvest the crystal at the Forge entrance. You are suddenly attacked by a strange dark beast, and must defend yourself. Defeat the Dark Beast. You now have a lightsaber crystal from the Forge entrance. Take it and the first blade's hilt to the ancient Forge and craft a new lightsaber.
Your task is to craft your lightsaber at the Forge. Keep going through the caverns and exit onto the Ancient Forge. Craft the lightsaber. Tell Qyzen to watch your back while you do it, as it will require a lot of concentration. Nalen shows up. Go and confront him at the base of the Forge. Trying to reason with him won't help, and a battle takes place at the end of the dialog. Defeat him, and speak to him again to decide his fate.
Allia, a fellow Twi'lek, pleads to you not to kill him. Your choices are:
The Jedi Council must decide (NEUTRAL)
I'll take him prisoner (LIGHT)
He has to die (NEUTRAL)
If you say the Jedi Council must decide, Keth asks you who will help defend the village. You can respond:
You can ask for my help
[Force Persuade] Have Hope
Find your own strength
Try the Force Persuade to instill hope in the Twi'leks.
After the encounter Qyzen Fess talks to you. He tells you that you are the Herald of Scorekeeper. Qyzen promises to follow you and serve you wherever needed.
It is time to report to Master Yuon Par and the Jedi Council at the Jedi Temple. Return to the Jedi Temple and head upstairs to the Council chambers. Master Yvon Par is there, as well as Master Jaric Kaedan, Master Satele Shan, and Master Syo Bakarn. You no longer a padawan. You carry a lightsaber. Master Satele asks you what should become of Nalen Raloch when he's well. Your possible responses are:
Train him as a Jedi (LIGHT)
Release him to his people (NEUTRAL)
Keep him prisoner (DARK)
Master Syo Bakarn says the Jedi Council judges you ready to accept your place as a Jedi, and asks Yuon to swear you in. But Yuon appears ill, and collapses. Master Bakarn tells you she is in grave condition and they haven't been able to heal her. They are sending Yuon to Coruscant. Their researchers there have been recovering artifacts from the first Jedi Temple. They may have something to cure Yuon. He instructs you to take a shuttle, and join Yuon on Coruscant. She will need your help. Qyzen says he will go with you.
When you reach Coruscant, go to the embassy in the Senate tower, and find a researcher called Attos Finn. He'll be expecting you.
This completes the mission "The Forge" and the last Jedi Consular class mission on Tython. The next mission, "An Afflicted Master", begins now.