Practised Manifester and Prestige Classes

[Vaz]

Example.

Ardent 2/Wu Jen 8/Cerebremancer 10

Can I take Practised Manifester more than once, one Improving Ardent Manifestation and one improving Cerebremancer to give me ML 20?

If not, why not?

[Aracor]

One simple reason:

Cerebremancer doesn't actually have its own manifesting to improve. It simply adds to your character's manifesting class (in this case ardent). So you can't apply practiced manifester to it.

[Karnith]

Because a cerebremancer gains "additional power points per day and access to new powers as if he had also gained a level in any one manifesting class he belonged to previously," levels in cerebremancer do not grant separate manifesting capabilities; they only advance the manifesting capabilities of another class. The class notes that "[t]his essentially means that he adds the level of cerebremancer to the level of whatever other ... manifesting class the character has, then determines ... power points per day, powers known, and manifester level accordingly," so, per your example, an ardent with levels in Wu Jen and Cerebremancer only has the ability to manifest powers as an ardent (as a demonstrative example, that character does not have the ability to learn or manifest cerebremancer powers, but only ardent powers). While you can take Practiced Manifester multiple times, the feat specifies that "each time you choose it, you must apply it to a different manifesting class," so you can only apply the benefit of Practiced Manifester to a single class once.

EDIT: Swordsage'd.