Light crystals

Light Crystals were featured in Soul Reaver 2. They were a door locking mechanism, presumably developed by the Ancient Vampires that could be opened with the use of the Light Reaver or Moebius' staff.

Raziel noticed Light Crystals shortly after the beginning of Soul Reaver 2, locking the door to the Time Streaming Chamber and the large outer doors to the Sarafan Stronghold. Raziel was unsure of their usage until he was able to gain the Light Reaver, at which point he discovered that the Reaver Bolts of the Light Reaver were able to activate the Crystals and unlock these doors.

Light Crystals were not seen in further games.