Handaxes have the interesting property of being light x3 crit weapons...I think you can only really exploit them with WM to get the ki critical to extend the crit range to 17-20...with multiple attacks you'll be critting for x4 damage quite regularly...Swash lends itself well to dualwielding (which is a natural for the handaxe) and allows enough Skill points..
Enter the yuan-ti handaxe master...
STR 14 (6)
DEX 18 (10)
CON 14 (6)
INT 18 (10)
WIS 8 (0)
CHA 10 (0)
1 stat increase to dex all other to INT (especially first 2)..
1 Ranger 1 Abler Learner
2 Swash 1 Weapon Finesse
3 Ranger 2 Two Weapon Combat Style Combat Expertise
4 Ranger 3 Toughness
5 Fighter 1 WF handaxe
6 Fighter 2 Dodge, Mobility
7 Ranger 4 (enter exploit of animal companion)
8 Ranger 5
9 Ranger 6 Improved Two Weapon Fighting, Spring Attack
10 Swash 2
11 Swash 3 Insightful Strike
12 Fighter 3 Greater Two Weapon Fighting
13 Fighter 4 Whirlwind Attack
14 Weapon Master 1
15 WM 2 Weapon Specialization Handaxe
16 WM 3
17 WM 4
18 WM 5 Improved Critical Handaxe
19 WM 6
20 WM 7
+3 Handaxes Flaming Sonic, Fox's Cunning, Bear's Strength.
Main Hand 4 attacks: 1d6 + 4STR + 8INT +2WS (17-20) x4 +3enhance +1d6flame + 1d6 Sonic
Offhand 3 attacks: same but only 2STR
Avg Main Hand Crit = 80
Avg Off Hand Crit = 72
in 5 rounds (which really doesn't take long) thats the potential for 7 x 5 x .2 = 7 crits (of course some of those are at lower chance to confirm, but for lower AC opponents expect a crit every round....now look again how big the damage on a crit is
)Kukri would be devestating too, but I thought handaxe was more interesting.