Well I can give you a pointer in the right direction, whether or not you will consider them what you're looking for or not I can't guarantee, however! I'll give Youtube links to each to make it somewhat easier for you.

Slayers Next OST - Xellos, His True Form
YouTube - Slayers Next OST - Xellos, His True Form

Slayers Song Biblie III OST # 07 / 20 - Darkness, nothingness, in other words, chaos
YouTube - Slayers Song Biblie III OST # 07 / 20 - Darkness, nothingness, in other words, chaos

SOUL EDGE (BLADE) THEME OF SOPHITIA (ARRANGE VERSION)
YouTube - SOUL EDGE (BLADE) THEME OF SOPHITIA (ARRANGE VERSION)

A lot of the Soul Blade OST could well help with what you're looking for, though a couple of personal faves are:

Soul Blade Bravely Folk Song Cervantes theme
YouTube - Soul Blade Bravely Folk Song Cervantes theme

Soul Blade A Desperate Struggle Colosseum theme
YouTube - Soul Blade A Desperate Struggle Colosseum theme

Divine Beast Dran - Dark Cloud
YouTube - Divine Beast Dran - Dark Cloud

Err yeah, there's a few to get you started, no idea how much use to you they'll be!