Health coil

The Soul Spiral also known as the Spirit Spiral was a symbol used particularly throughout the Soul Reaver arc of the series.

The symbol is most prominently used as Raziel's health meter, but has many other uses throughout the series. A similar symbol was originally meant to represent the 'Spirit Glyph' and 'Spirit Reaver' in Soul Reaver but both were removed before the game's completion and the Spirit symbol was redesigned.

Ruins in the Great Southern Lake in Soul Reaver 2 also bear this symbol (along with the redesigned one), heavily suggesting that this was meant to be that game's Spirit Forge.

The symbol also decorates much of the Underworld in Soul Reaver.