Dread Necromancer with right feats can boost a lot of our undead minions. Also in end become a lich (dread necro is base class). Another cohort candidate is archivist (a scholar/research geek with divine spells). Or enter some PrC and go bit crazy. Like go example Virtuoso (https://www.wizards.com/default.asp?x=dnd/ex/20011207) class after 8th level as dread necro and pick Requim feat (so all bardic music goodness affects undead minions and Song of Fury is fun plus Calumny can be useful to turn people against the order and work for our goals). Once maxed PrC at 18th level (it's crappy PrC but dread necro is crappier, just wanted keep casting levels), then when I have 9th level necromancy spells I could enter Dirgesinger final 2 levels if we go past level 20th somereason.<br/><br/>Only problem is to get perform as class skill and it can be solved by taking apprentice feat (as human as second feat goes to tomb tainted soul).