This is a 3.5 ascetic Rogue. Stat array: ++WIS>+DEX>+CON>STR>-INT>-CHA. I gave him fortitude so they couldn't do to him what he was doing to others. Start him out with quarterstaff until he gets UAS (they cost nothing), then buy Scorpion Kama (applies UAS to damage with Kamas) and enchant them when possible.
Ragged shadow (they look unassuming): They work in groups. one blinds the victim, the others set up flanks and use unarmed FOB (poor bastard). Pump up the damage with fiery fist.
R1 SA 1d6, trap finding, improved initiative, great fortitude
R3 SA 2d6, trap sense +1, intuitive attack (adds WIS to attack roll)
M1 *stunning fist, flurry of blows, UAS 1d6
M2 *fiery fist (use SF[swift] for +1d6 fire to all UAS that round), evasion
R4 uncanny dodge, falling star strike from OA (SF blinds opponents)
R5 SA 3d6
R6 trap sense +2
R7 SA 4d6, ascetic rogue (+2 to stun DC), UAS 1d8
R8 improved uncanny dodge, UAS 1d10
R9 SA 5d6, trap sense +3
R10 special ability (opportunist), improved natural attack+UAS 3d6
R11 SA 6d6
R12 trap sense +4
R13 SA 7d6, special ability (crippling strike),
superior UAS 3d8
R14 UAS 4d8
R15 SA 8d6, trap sense +5
R16 special ability (improved evasion), ability focus SF (+2 to stun DC)
R17 SA 9d6
R18 UAS 6d6
R19 SA 10d6, improved stunning fist (+2 stun DC)
WIS is the primary stat because it increases your attack rolls, stunning fist and AC. The Kamas are for stuff you can't hit with your normal UAS.