This is an idea I've been throwing around. I originally started out trying to create a switch hitter ranger. I then read the unchained rogue and the elven curve blade, so I changed thought of a two-handed build that has low strength. I've been away from RPG's for a while, but I feel like it might progress a little slow. I'm starting to think that the slower BAB is hurting the build.
Honestly, this might be easier with a Strength based build. Problem is that the story requires it to be an elf... I might go for an archer ranger. The Con penalty hurts.
Race: Elf (Thinking of using the Silent Hunter alternate racial trait)
Classes: Ranger/Unchained Rogue
Abilities: 20 points
Str 9
Dex 20 (+1 at lvl 12, +1 at lvl 16)
Con 13 (+1 at lvl 4)
Int 10
Wis 13 (+1 at lvl 8)
Cha 7
Put lvl 20 ability increase to either strength or charisma to negate a -1?
Levels:
1 Ranger
2 Rogue
3 Ranger
4 Rogue
5 Rogue
6+ Ranger
Feats
1 Weapon Focus (Elven curve blade)
2 Weapon Finesse (Rogue)
3 Toughness; Power Attack (Ranger)
4 Improved Initiative (Rogue talent combat trick)
6 Endurance (Ranger); Skill Focus (Acrobatics)*
9 Improved Critical (Elven curve blade); Great Cleave (Ranger)
12 Critical Focus
13 Furious Focus (Ranger)
15 Vital Strike
17 Improved Sunder (Ranger)
18 Blinding Critical
*Not sure about the skill focus. Thinking of flanking bonuses.
So, by the time the Unchained Rogue levels (character level 5) are all acquired, the character has the following attacks:
Elven curve blade +10 (1d10+7/18-20/x2, 8-17, or 12 average?)
w/ power attack +8 (1d10+13/18-20/x2, 14-23, 18 average?)
w/ power attack + sneak attack +8 (1d10+13/18-20/x2 +2d6, 16-35, average 24?)
Attacks assume basic weapon without enhancements or special modifiers.