When Raziel originally gained the Wraith Blade in Legacy of Kain: Soul Reaver, it effectively had two companion enhancements; the green Spectral Reaver and the blue Material Reaver, with the Material Reaver the default manifestation of the blade in the Material Realm. In Soul Reaver the Material blade would only manifest when Raziel was at full health in the Material plane. Once manifest, it was noted for sustaining Raziel's own Material manifestation; preventing his health from being depleted unless he took damage from combat. In combat, the blade was more powerful than other standard weaponry and was able to execute a 'charged' fatal blow on stunned enemies. The Material Reaver could be used to open certain Sealed doors, enhanced with the Telekinetic force projectile relic to produce Reaver bolts and also optionally be imbued with elemental Fire, creating the Fire Reaver[SR1].
The blade returned in Soul Reaver 2, where it acted in much the same manner initially; only manifesting in the Material Realm when Raziel's health was full. Shortly into the game however, the Wraith blade grew in strength after meeting its former self in William's chapel. After this incident the Material Reaver could be summoned and dismissed at will, but this had a price as in combat the Reaver's would gradually fill the Reaver bar which encircled Raziel's Health spiral, increasing the power of the blade tremendously but devouring the Souls of its victims before Raziel could feed and eventually turning its hunger on Raziel when completely filled. As in Soul Reaver, the blade could also be used to open certain Sealed doors, fire Reaver bolts and also be imbued with several elemental powers.[SR2].
The Material Reaver featured again in Legacy of Kain: Defiance where it was for the first time identified as a distinct version of the Wraith Blade, separate from the Spectral Reaver. The Material Reaver was now permanently present as Raziel's default Wraith blade manifestation in the Material Realm though it could no longer be dismissed. Similar to Soul Reaver 2, the Material Reaver could be fed on enemies Souls to fill the Reaver charge and allow Raziel to use Charged attacks (which increased attack damage) and Reaver spells which included splash damage on nearby enemies) in combat. The Material Reaver could interact with other objects and enemies in the Material Realm, the blade could also be used to open certain Sealed doors, and also be imbued with several elemental powers. Both the Spectral and Material Reaver would ultimately be superseded late in the game by the Spirit Reaver[DEF].
The colours of the Spectral and Material Realms highlight features of their respective realms - with the green of the Spectral Reaver reflecting the colour of Souls and the Material Reaver usually depicted as being the same shade as Raziel's material body[SR1][SR2][DEF].
In all games the Material Reaver has been planned to be superseded by a more powerful default Wraith blade at the end; these include the Ariel and Kain Reavers in early versions of Legacy of Kain: Soul Reaver and the Spirit Reaver in Soul Reaver 2, The Spirit Reaver eventually replaced it in Defiance[DEF-C12][DEF].