Looking for a feat and other questions

[Human Paragon 3]

Hi guys. Need a little assistance.

First, I am looking for a feat that lengthens the duration of an intimidate check used to demoralize an opponent in combat. If I'm not mistaken, it makes the shaken effect last for a # of rounds equal to your Cha modifier. It may just make it last for a certain # of rounds though, not sure. I dont know what it's called or what book it's in, but I am 90% sure it exists.

Second, I'm looking for tips on improving my friend's dragon shaman build. It is for a level 1-5 game and he is focussing on charisma skills including intimidate. He already has the feat Nimbus of Light from the BoED. Good ways to boost his AC would be helpful, since we are playing in a setting with little available armor and he's feeling a bit nerfed by this.

[Person_Man]

Optimizing Demoralization.

Other things that might help you with a Fear/Demoralize build:

Daunting Presence: You can take a standard action to render an opponent Shaken for 10 minutes. Has no effect on enemies who are already Shaken. (Libris Mortis and Miniatures Handbook).

Frightful Presence: Gives you a dragon's frightful presence. (Draconomicon. Can also be purchased with a graft from Races of the Dragon).

Dreadful Wrath: Gives you a frightful presence, though the mechanics are worded slightly different from the Draconomicon's version. (Player's Guide to Faerun)

Divine Censure: Spend a turn undead attempt to attempt to render all Evil Outsiders Shaken. (Fiend Compendium II)

Disciple of the Eye: Enemies must Save or be Shaken each time you attack. (Races of the Dragon)

Avenging Executioner: Enemies must Save or be Shaken every time you damage them with Sudden Strike. And you treat scared opponents (shaken, frightened or panicked) as flat-footed. Complete Scoundrel.

Anything that debuffs: Hexblade, Blackguard, spells, anything that renders your enemy Sickened, etc.

Keep in mind that tons of enemies are immune to fear - more so then precision damage. So don't put too many eggs into this particular basket.

Also, Nimbus of Light is a really poor feat, as are almost all other feats that provide small static bonuses.