This is going to be the cohort for a slightly modified multithreat build of DavidWL's
Chameleon multi-threat It should hit the points that build's cohort needed (namely the Marshal aura and focus on Charisma skills) while being able to contribute in combat as well.
Cheese: Ghostwalk variants: No Calling and Flexible Advancement, character can borrow money for Savage Species ritual to obtain evil subtype, takes 2 Flaws at 2nd level (because dying is traumatic, otherwise takes flaws at 1st and retrains/DCFS/Psy Ref as needed), LA buyoff.
Brief Feat Descriptions: Ghost Hand and Poltergeist Hand are crappy prereqs for Poltergeist Rage, which allows one to use the Violent Thrust form of Telekinesis for 2 Charisma damage, which is eliminated through 1 point of incarnum invested in the unbound Strongheart Vest. Improved Ghost Hand is sustained force Telekinesis.
Abilities (32 point buy)[spoiler]Str 5(-) (8-3 Age)
Dex 5 (8-3 Age)
Con 12 (14-3 Age +1 Bloodline)
Int 16 (14+2 Age) (note Int 14 is the minimum to allow FoP entry@3rd level)
Wis 12 (12+2 Age-2 Magic Blooded)
Cha 38 (18 base +4 level +6 Cloak +5 Wishes +2 Age +2 Magic-Blooded +1 Bloodline)[/spoiler]
Build Stub[spoiler]Old Magic-Blooded Dvati Cloistered Cleric 1/Eidolon 2/Fiend of Possession 6/Marshal 1/Master of the Unseen Hand 4/Bloodline 3 (Applied to FoP and Improved Caster Level from MotUH)
Cleric Domains: Incarnum, Open
Bloodline: Celestial/Devil/Demon all work (needs +1 Con and +1 Cha)
1 Incarnum Spellshaping (Domain bonus), Shape Soulmeld (Strongheart Vest)(Level), Knowledge Devotion (traded from Domain)
2 Ghost Hand (Flaw), Poltergeist Hand (Flaw) Poltergeist Rage (Eidolon bonus)
3 Item Familiar, Improved Poltergeist Hand(Eidolon bonus)
6 Open
9 Mindsight*
10 Skill Focus (Diplomacy)(Marshal Bonus)
12 Open
*using the FoP's telepathy with a host
[/spoiler]
Combat
[spoiler]Attack: 15@+45 (17 from level, 7 from Improved Caster Level, 1 from Masterwork, 1 from usual Knowledge Devotion result, 19 from Charisma)
Damage Output: 4d6/level, maxing at 60d6+90(15 Colossal Siangham w/ chained greater magic weapon and usual Knowledge Devotion result) average 300/round
HP 1/2(6+3d8+6d6+4d4) +14 = 39.25 each
Saves: F:11 R:3 W:17
AC: 26 (10+19 Deflection-3 Dex)
Needless to say, they're never going to be outside of an item.[/spoiler]
Misc.[spoiler]
Marshal Aura: Demand Fortitude
Equipment: Savage Species ritual, Cloak of Charisma +6, 15 Masterwork Colossal Sianghams, 980 gold free
Item Familiar: Quiver of Ehlonna Int 16, Cha/Wis 12
Special Abilities: Increased Sapience, Spell Use
Skills: 103 skill points@ Int 16
Bluff/Diplomacy/Intimidate 20
Knowledge: Dungeoneering, Local, Nature, Psionics, Religion, The planes: 1
Knowledge: Arcana 6 (2 CC)
Hide 19 (2 CC)
Concentration 8[/spoiler]