Raziel first encountered the Sun Disk when he was able to enter a two-tiered chamber at back of the Dark forge and saw the glowing Sun Disk in a holder on the upper level. Making his way through an upper entrance to the nearby main activation chamber, Raziel found an empty holder for the Sun Disk and was able to make his way through some of the other chambers of the forge. Solving the puzzle of the 'eclipse room', Raziel was able make his way to the upper level of the two-tiered room and recover the Sun Disk.[Soul Reaver 2][Soul Reaver 2/3][Soul Reaver 2 strategy guide (Prima)]
The Sun Disk was a circular golden disk artifact with a basic sun motif marked on the face of the disk. Once gained the Sun Disk significantly limited Raziel's abilities - preventing him from Climbing, Gliding, entering Combat, manipulating objects or DevouringSouls. If placed on the ground, the key would quickly return to its point of origin.[Soul Reaver 2][Soul Reaver 2 manual]
Returning to the main chamber of the forge, the main doors opened with the presence of the Sun Disk and Raziel was able to place the disk in the holder at the back of the room. Continuing through the forge and solving the puzzle of the Sundial and Reflector room, Raziel was able to position an identical disk to bounce natural light around the forge and down onto the Sun Disk in the main activation chamber, with the resulting 'eclipse' effect on the forge crystal causing the forge to be activated and the Reaver to be imbued with elemental Darkness, gifting Raziel with the Dark Reaver.[Soul Reaver 2][Soul Reaver 2/3][Soul Reaver 2 strategy guide (Prima)]
The Sun Disk Room
The original placing of the Sun Disk
Raziel holding the Sun Disk
Final Sun Disk door opened by presence of Sun Disk
Sun Disk Door texture
Similar Sun Disk reflector on ceiling of Sundial Room
The Sun Disk acts similarly to the later Reflector seen in the Light Forge - being placed to reflect Sunlight-rays through the forge. Despite their similarity in use and appearance, the markings on the two are different.[Soul Reaver 2]