Firstly, the basic information:
-One-shot.
-Level 6. 32 Point Buy. 1 Flaw 1 Trait. Max HP. Fractional BAB/Saves. Normal WBL.
So far the only thing set in stone is totemist 2, and the Bonus Essentia and Improved Capacity(Name?) feats, and the focus on manticore belt. This nets 4 ranged attacks as a standard action. Sadly, 4x1d6 is pitiful, and I need a source of bonus damage. Assume Manticore Belt's attacks are ruled to be ranged natural attacks.
The obvious route is skirmish, however, as swift hunter is not an option with these levels, the value of this is diminished. Even then, taking more than 1 level seems a waste. The original plan was to play a dragonborn so as to get access to Dragonfire Strike for another 1d6, however, I'd like to ponder other options, as the DM has hinted at an undead theme.
I seem to recall someone else's build involving the Targetter Fighter and/or the Dead Eye feat. +8ish damage per attack is nice, but again, half of it is gone against undead. It also seems rather feat intensive.
An unorthodox option would be to use touch of golden ice, however this is situational.
(Also, I think a friend MIGHT be playing dragonfire bard, so this topic may be moot.... Still, hope you can give me some ideas.)