A Shadow-walker archetyped Unchained Rogue/ Shadowdancer.
You can level the rogue to 5, as is required for Shadowdancer, level the Shadowdancer to 4, and then work on the Rogue until 14, and leveling the rest of the way to Shadowdancer. By spending a rogue talent on a combat feat and an advanced rogue talent on a regular feat, you can have Outflank with Dimensional Savant by then. At 16, with another level of Shadowdancer, You can get Double Debilitating Injury, and by 17, Greater Two Weapon Fighting. You would be... A terrifying blur of incapacitation by 17.