Sword of Descension is only obtainable for PS4 and PS5 Travelers. It is automatically available via the Mail system when Travelers start their adventure.
Players on different platforms can obtain the weapon by logging into the game on PS4 or PS5 and activating the cross-save feature. However, the weapon’s effect (Descension) only applies when playing on PlayStation.[1]
Only one copy is given, as such, the maximum refinement level is one.