In addition to The Pillar Glyphs, the design of Soul Reaver 2 initially included an augmentation for each of the Reavers, including the Deleted Elemental Reavers. As described in the Pillar Glyph article, it seems that the deleted Glyphs of Soul Reaver 2 would not have been weapons (although they may have been useful in combat for other reasons), and the Reaver upgrades would have taken the place of the Soul Reaver Glyphs in that regard.
The August 2000 issue of Electronic Gaming Monthly describes three of these deleted upgrades:
You'll find seven reaver augmentations that bestow special charge-up moves. Find the Fire Reaver augmentation and you can cast a ring of fire by holding the attack button. The Dark Reaver augmentation gives you temporary invisibility, the Light Reaver power-up will illuminate an entire room and blind light-sensitive enemies, etc.
The invisibility effect is still present (but unused) in the final version of the game, and can be activated using Playstation 2 cheat device codes (see Codes (Playstation 2 Cheat Device)). Screenshots are available at the end of this article, and the video available in The Full Ring Menu article depicts it as well.
No screenshots or video of the other upgrade abilities are known to exist. It is uncertain if any of them were implemented in the game before they were removed from the project entirely.
The locations where Raziel would have obtained these upgrades and what would have been necessary to unlock them are currently unknown.
The special powers originally designed for the Reaver Upgrades were included in Defiance as each Reaver's built-in charge ability, rather than as a separate add-on.