Here is what I have been using lately among some friends. What would you change? He still has plenty of weaknesses.
A quick note on the rest of the rules I use:
1. Aspiring Sorcerers are ML:2 and generate 1 power from the Discipline of Tzeentch.
2. Chaos Sorcerers with Mark of Tzeentch are ML:3 and gain Fearless. They generate 2 powers from the Discipline of Tzeentch.
3. Discipline of Tzeentch: http://www.dakkadakka.com/dakkaforum/posts/list/0/472534.page#4699750
4. Terminators with the Mark of Tzeentch become Rubric Terminators and have Ap3 Bolters, are Slow and Purposeful, and Fearless.
5. So long as a Psyker with the Mark of Tzeentch is in a Rubric or Rubric Terminator unit, the unit trades out Slow and Purposeful for Relentless.
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Ahriman, Chief Librarian of the Thousand Sons 225pts
WS 5---------
BS 5---------S 4----------T 4--------W 3-------I 5--------A 3--------
LD 10--------
SV 3+/4+
Unit Type: Infantry, Independent Character, Psyker (
Mastery Level 4) Unique
Wargear: The Black Staff, Inferno Bolt Pistol (Ap3), Frag and Krak grenades
Special Rules: Mark of Tzeentch (Included in profile), Book of Magnus, Mastery of Sorcery
Master of Sorcery: Ahriman automatically passes psychic tests. He never suffers a wound from Perils of the Warp- he loses a Warp Charge point instead.
The Black Staff of Ahriman: Force Stave. Ahriman may use multiple Witchfire powers in a single turn.
The Book of Magnus: Before deployment, select any Psychic Discipline in the Warhammer 40,000 rulebook, or the Discipline of Tzeentch. Ahriman knows all powers from the chosen discipline for this game.