moon knight in dnd 3.5

[Rentirith]

How would i build a moon knight type character? For those of you who dont know him, here is his wiki page: http://marvel.wikia.com/Marc_Spector_(Earth-616)
For those who dont know and dont want to read a lot, He is a schizophrenic version of batman who is ok with killing.

I am looking for a lvl 20 idea. You dont have to plan out every feat or prestige class, but just a general idea of what to do. I was thinking monk would do well, based off the unarmed/ninja equipment, but the crazy side wouldnt work with the monk's lawful nature very well. I am also hesitant to take sword sage because i dont understand ToB stuff very well, and Moon Knight doesnt use magic powers.

I know im being a bit picky, but any help is appreciated.

[Sagetim]

Straight Possessed Fighter/Rogue, with a demon of the week possessing him to tell him to do this that or the other thing? You don't have to use a weapon as a fighter. You could pick up improved unarmed strike, weapon focus (unarmed strike) weapon spec (unarmed strike) and so on with fighter feats, and enjoy the delicious crunch of sneak attack damage. I'm sure you could find a way to cheese it by either tripping or grappling someone and kidney shotting them to victory.

[(Un)Inspired]

Batman wizard.

Refluff all your spells as karate moves to avoid having any magic powers.

[torrasque666]

Batman wizard.

Refluff all your spells as karate moves to avoid having any magic powers.
Wiggity Wiggity Woo with my kung fu mastery I am now a demon.