Rulebook and codex psychic powers mixing

A buddy of mine believes that he can mix psychic powers from Both his codex and the rule book.  We looked over the FAQ and what the codex says about taking powers for psychers and he is convinced that the codex allows it and that the FAQ is only referring to the old Eldar codex.  
I say no but what do you guys think?

I think your friend needs to take another look at the FAQ

Quote :

Q: Can psychic powers be mixed and matched from the psychic disciplines and those found in the Codexes? (p418)
A: No. You may select from the psychic powers listed in the Codex as normal or swap them for a number of rolls on the psychic disciplines tables.

I pointed it out a time the time. He still chooses to believe otherwise.

If your friend wants to use Psychic Powers from C:Eldar and the BRB, he in fact can take powers from both as the Codex gives permission to do so.

Pg 70 C:Eldar... "Eldar Psykers have access to those psychic disciplines found in the Warhammer 40k rulebook that are listed in their army list entry. In addition, they may choose their powers from the Runes of Battle or Runes of Fate as stated in their unit entry. For each Mastery Level he has, a Psyker may make a roll on one of the tables available to him."

The last sentence actually may clarify it for me.  After seeing it again I think he may be right.

then Eldar psykers are incredibly powerful.

Sorry, I misunderstood the question. Yes, you can roll on the tables in the new codexes (6e) and also on the BRB tables if permitted, as is the case with the Farseer. What you cannot do is take, for example, a Rune Priest with Jaws of the World Wolf, from the SW codex, and another power from the BRB disciplines. You must choose either all codex, in the case of 5e or 4e codexes, or all BRB. No mix and match.

Just to chime in, the other interpretation is one that I've heard, and been reason to me. Not sure on it, but:

Quote :

Q: Can psychic powers be mixed and matched from the psychic disciplines and those found in the Codexes? (p418)
A: No. You may select from the psychic powers listed in the Codex as normal or swap them for a number of rolls on the psychic disciplines tables.

....can be taken to mean INDIVIDUALLY. It doesn't really make it absolutely clear whether you replace ALL your Psychic Powers for a number of rolls, or whether you can replace them INDIVIDUALLY for rolls.
As I said, I always thought otherwise, but when it was reasoned out to me I couldn't think or find a good argument against this idea.

Huh... Frankly, to my understanding, the Eldar codex and the FAQ is starting to contradict eachother a little. I mean, if the codex say
"For each Mastery Level he has, a Psyker may make a roll on one of the tables available to him."
, that should mean the psyker can roll on any available table for each mastery level. But if the FAQ says
"You may select from the psychic powers listed in the Codex as normal or swap them for a number of rolls on the psychic disciplines tables."
, wouldn't that mean you have to swap everyone for the table powers? Or am I completely lost now?

The FAQ does need updating really to make it clear that it is referring to older codexes that either gave you fixed powers or allowed you to choose powers rather than roll randomly on a table. As far as I am aware the position as it stands is that the following codexes still have powers that can be freely selected or that are specified for the psyker:

Blood Angels
Space Wolves
Grey Knights
Imperial Guard
Orks (you roll randomly each turn on the table in the codex)

The FAQ actually explains this reasonably (for GW) well.

Quote :

PSYCHIC POWERS
A Blood Angels Librarian (including Mephiston) may use the psychic disciplines found in the Warhammer 40,000 rulebook, instead of those in Codex: Blood Angels. If he does so, generate
two new powers from the Biomancy, Divination, Telepathy or Telekinesis disciplines (in any combination) before armies are deployed.

For all other codexes, you can roll on any of the tables that are permitted to you in any combination (subject to any specified limits or minimum requirements).