The way understand it is that there are 4 dark age relics to find named Dvalin followed by numbers. The last 3 digits denote which one you have found(001,002 etc) each time you find one you hand it into banshee. After that you need to wait until The First Firewall mission on earth is released again. This is a 1 day chance to start the quest. If you do not complete that mission on that day then you will have to wait for it to come round again. Once you complete the mission you will find a curious tranceiver in your inventory. You need to input 4 codes into this(easily found with a Google search) which then unlocks a solo mission which you have to complete within 4 mins. Once done you will then have to charge a core by doing warsat public events and a few other things(can't remember what exactly) then hand that to banshee. The quest will then appear to just stop until the following reset when you get a special sabre strike mission. Upon completion of that you receive the weapon. As long as you finish the first firewall mission I believe the quest stays with you until complete, meaning you don't have to do everything in 1 day just ensure you complete the first mission. Hope that makes a bit of sense and helps you out. Edit: yes the relics will still drop and are rng based. I got mine mainly from public events.