I dug through my old Czech PlayStations magazines and decided to scan everything LOK related. The articles are very interesting since they contain very early images and information which never got into the game itself. I will post more stuff soon.
This first set of pages is from PSM no. 12, which includes a Soul Reaver review. Apart from getting Raziel´s name wrong ("Ralziel"), it features a lot of very early screnshots of areas and template enemies. It even features the test room and early Glyph icons. The review also mentions imbuing the Soul Reaver with elements of water, fire, sun light or souls of your enemies.
The "clawed" title
Early shots of Melchiah, Dumah, Ruined City and the Lighthouse
Early Rahab, the test room with glyphs and Blood Omen comparison
More shots of early enemies
Shot of Abyss and some strange star ornament in the Cathedral
Zephon and Glyphs
Undercity Lair screen on top left
Here is the preview from PSM no. 11. It mentions that Raziel constructed his wings right before Kain got his own, or that Raziel will face Kain three times and Kain having the strength of eight bosses. It also describes that by imbuing the Soul Reaver into fire, ice, water, etc., it can destroy specific enemies.