The Telvanni Codex is a carriable spellbook containing many levelled spells that you may learn provided you have sufficient mastery in the relevent magic school. You may only learn one random spell at a time by accessing the codex from your inventory.
The principle aim of this MOD is to put back all of the spells from Morrowind that were omitted in Oblivion, even those that were useless or now redundant in Oblivion. In keeping with OB, their effects are largely improved over MW versions and there are several versions of most spells at different mastery levels, usually reflecting the original named MW versions. In fact the Codex contains a total of 78 spells, 50 of which are faux Morrowind.
The Morrowind spells/spell classes included are:
Alteration: LEVITATION, JUMP, SLOW FALL, LOCK, SWIFT SWIM
Mysticism: ALMSIVI INTERVENTION, DEVINE INTERVENTION, MARK, RECALL
Illusion: BLIND, SOUND, SANCTUARY
Destruction: POISON, WEAKNESS TO POISON
Restoration: CURE POISON, RESIST POISON
Note that the poison spells are to mirror the magical poison available in MW and are the only spells that may be cast against you by NPC's, etc. They are different and independent of the physical poison and sustained damage effects in OB.
Additional spells/spell classes added to redress the balance of the schools and classes include:
Alteration: Vampire Swift
Conjuration: CALL CREATURE, CREATE ARROWS
Destruction: Holy Light, Holy Water
Illusion: Mass Mesmerize
Mysticism: Apperate
Restoration: FOCUS *magic skill*
All of the spells work as intended with very few issues. Finding and using the Telvanni Codex is a mini quest in itself. Most spells are unique, even within a spell class, but this MOD also includes another artifact that allows you to unlearn any you dont want.
This MOD does not require a restart and should not interfere with any other MODs.
Much more information is given in the README file and the individual spells are documented in the Codex itself.