A bit of random brainstorming on this:
Skills you need: Bluff 6, Knowledge (arcana) 5, Knowledge (the planes) 5, Knowledge (religion) 8, Spellcraft 8.
- Considering Duskblade 3 for Arcane Channeling and the base save prereqs, you have 2 more levels to gather the skills you need.
- Assume Human with an Int of 12 for some flexibility in skills and ability to cast the few Duskblade spells you get access to. This leaves us with 12 skillpoints from your Duskblade levels, in any knowledge skill or in spellcraft.
- You'll want Bluff as a class skill for at least one level. Alternatively, grab Apprentice (Criminal) from DMGII, if allowed. More than 2 skillpoints per level is nice but not strictly necessary - you'll hit exactly the required 32 skill points if you can buy them all as class skills with only 2 SP/lvl (= 4 with int 12 and human).
- Possibilities include
Feat Rogue, the aforementioned
Cloistered Cleric, Hexblade,
Human Paragon in addition to the ones mentioned earlier in the thread. Two levels of Monk or
the evil Paladin variants are possible only if you can get bluff through Apprentice or another feat.
EDIT: Actually, since Unearthed Arcana isn't on the list, can you even use those variants? Are you limited by those books exactly, is the SRD fair game or is it just everything you have access to (the latter case adding
several more options)