Skill Points Allocation Guide

Dual Blade Rogue Skills
Dark Sight: (20) Use MP to hide behind the shadows. While hiding, the enemy won't attack, but you can't attack back either. All movements other than attacking are available. It's temporary, so after a while, you'll be back to normal.
Disorder: (20) Temporarily decreases the morale of an opponent. Its DEF and ATK will suffer, and the attacking enemy will suddenly stop attacking. Can't perform the attack on an enemy that's already in disorder, however.
Double Stab: (20) Use MP to quickly stab an enemy twice at once using a dagger
Nimble Body: (20) Increases accuracy and avoidability.

Skill Build
10: +1 Double Stab (1)
11: +3 Double Stab (4)
12: +3 Double Stab (7)
13: +3 Double Stab (10)
14: Save SP (3)
15: Save SP (6)
16: Save SP (9)
17: Save SP (12)
18: Save SP (15)
19: Save SP (18)
20: Save SP (21)

Skills so far:
Dark Sight: 0
Disorder: 0
Double Stab: 10
Nimble Body: 0

Reasoning for this build: 10 Double Stab is needed to unlock Triple Stab in 2nd job, which will instantly replace Double Stab. Rest of the SP is saved as Dark Sight is not needed at these levels.

Semi-Dualer Skills
Katara Mastery(20): Increases the Katara mastery and accuracy. It only applies when the character has a Katara in hand.
Triple Stab(10): Attack your enemies 3 times in rapid succession. Up to 3 enemies
Katara Booster(20): Use HP and MP to temporarily boost up the attacking speed of the dagger. It only applies when the character has a dagger in hand.

Skill build
20: +10 Triple Stab (10), +5 Katara Mastery (5), +6 Booster (6)
21: Save SP (3)
22: Save SP (6)
23: Save SP (9)
24: Save SP (12)
25: Save SP (15)
26: Save SP (18)
27: Save SP (21)
28: Save SP (24)
29: Save SP (27)
30: Save SP (30)

Skills so far:
Dark Sight: 0
Disorder: 0
Double Stab: 10
Nimble Body: 0
Katara Mastery: 5
Triple Stab: 10
Katara Booster: 6

Reasoning for this build: There really isn't too much to this job advancement. At level 20 automatically get 10 Triple Stab, 5 mastery, and 6 booster. Mastery is not going to really raise your damage that much it'll mostly raise your Katara hits to be more even with your dagger hits.. it's not that important atm and the points are better saved.

Dualer Skills
Endure(20): Additional recovery for both HP and MP even while hanging still on a rope or a ladder. The higher the level, the faster the recovery time, along with recovering additional amounts of both MP and HP.
Self Haste(20): Boost your own speed, then boost the jump of those around you
Fatal Blow(20): Use MP to attack one enemy up to 8 times
Slash Storm(20): Use MP to attack multiple enemies multiple times. Attack 6 Enemies

Skill build
30: +20 Self-Haste (20), +5 Slash Storm (5), +7 Fatal Blow (7 - 1 SP from Slash Storm mastery book)
31: +3 Fatal Blow (10)
32: +3 Fatal Blow (13)
33: +3 Fatal Blow (16)
34: +3 Fatal Blow (19)
35: +1 Fatal Blow (20), +2 Slash Storm (7)
36: +3 Slash Storm (10)
37: +3 Slash Storm (13)
38: +3 Slash Storm (16)
39: +3 Slash Storm (19)
40: +1 Slash Storm (20), +2 Katara Mastery (7)
41: +3 Katara Mastery (10)
42: +3 Katara Mastery (13)
43: +3 Katara Mastery (16)
44: +3 Katara Mastery (19)
45: +3 Booster (9)
46: +3 Booster (12)
47: +3 Booster (15)
48: +1 Booster (16), +2 Disorder (2)
49: +1 Disorder (3), +2 Dark Sight (2)
50: +3 Dark Sight (5)
51: +3 Dark Sight (8)
52: +3 Dark Sight (11)
53: +3 Dark Sight (14)
54: +3 Dark Sight (17)
55: +3 Dark Sight (20)

Skills so far:
Dark Sight: 20 (max)
Disorder: 3
Double Stab: 10
Nimble Body: 0
Katara Mastery: 19
Triple Stab: 10 (max)
Katara Booster: 16
Endure:
Self-Haste: 20 (max)
Fatal Blow: 20 (max)
Slash Storm: 20 (max)

Reasoning for this build: At the very start you max out Slash Storm since it is your most useful skill out of everything given to you at the current level. 5 Slash Storm is useful as a aggro skill + gives you some good mobility. Fatal Blow is then maxed since it is your strongest 1v1 skill till 4th job. Slash Storm is maxed after, giving you full mobility + it's great for MP3 since you'll be training there soon after it's maxed. Mastery is then raised to 19 to make your attks fully stable. 16 Booster gives a good amount of time and is only 30 seconds off from Self-Haste on timer making it easier to keep up with both.
Now just max Dark Sight since there isn't much else better to put points in.

Blade Specialist Skills
Tornado Spin(20): Strike many of your enemies quickly with a strong spin attack.
Flash Bang(20): Toss a few flash bangs on the ground to decrease a number of your enemies' accuracy for a duration.
Flash Jump(20): While in the air after a jump, use this skill and the arrow for a second jump. The higher the skill level, the farther the distance for the jump.

Skill build
55: No SP gained upon job advancement.
56: +1 Tornado Spin (1), +2 Flash Jump (2)
57: +3 Flash Jump (5)
58: +3 Flash Jump (8)
59: +1 Flash Jump (9), Save SP (2)
60: Save SP (5)
61: Save SP (8)
62: Save SP (11)
63: Save SP (14)
64: Save SP (17)
65: Save SP (20)
66: Save SP (23)
67: Save SP (26)
68: Save SP (29)
69: Save SP (32)
70: Save SP (35)

Skills so far:
Dark Sight: 20 (max)
Disorder: 3
Double Stab: 10
Nimble Body: 0
Katara Mastery: 19
Triple Stab: 10 (max)
Katara Booster: 16
Endure:
Self-Haste: 20 (max)
Fatal Blow: 20 (max)
Slash Storm: 20 (max)
Tornado Spin: 1
Flash Bang: 0
Flash Jump: 9

Reasoning for this build: 1st point is placed into Flash Jump for some extra mobility, followed by 1 point in Tornado Spin and finishing up with 9 Flash Jump then saving the rest.
The reason we only get 1 point in Tornado Spin is because with GMS's available training options at these levels you'll either be training at MP3, Windraider, or Golden Temple.
MP3 you'd be using Slash Storm due to the line of huge mob, Tornado Spin doesn't have much need or use here.
Windraider has a medium - low spawn this is a spot where you'll be just using Triple Stab. Tornado Spin at 1 is great here because it rushes 3 monsters, and in conjunction Triple Stab hits 3 monsters.
Golden Temple is the same deal with Windraider pretty much.. it has a very low spawn but great exp gain.
The points you can save for your 3rd+ skills are more valuable atm also rather then getting higher Flash Jump or Tornado Spin.
And you won't really be using Flash Bang till 4th job so it can wait for now.

Blade Lord Skills
Bloody Storm(10): A more advanced version of Slash Storm. Attack even more enemies quicker than before.
Advanced Dark Sight(20): Attack while in Dark Sight. With a certain probability, remain in dark sight after attacking.
Mirror Image(30): For a certain amount of time, your alternate self will appear, repeating your every move. There's no real stamina in it, and it will disappear after some time.
Owl Spirit(20): If your owl attacks and kills the enemy, your next few attacks will be increased by 1.5 times.
Upper Stab(20): Pop your enemies into the air. While your enemies are in the air, they receive more damage
Flying Assaulter(20): Attack in a downward, diagonal spiral to strike your enemies from above.

Skill build
70: +20 Flying Assaulter (20 - 1 SP from FA mastery book), +10 Bloody Storm (10), +7 Mirror Image (7)
71: +3 Mirror Image (11 - 1 SP from MI mastery book)
72: +3 Upper Stab (3)
73: +3 Upper Stab (6)
74: +3 Upper Stab (9)
75: +3 Upper Stab (12)
76: +3 Upper Stab (15)
77: +3 Upper Stab (18)
78: +2 Upper Stab (20), +1 Tornado Spin (2)
79: +3 Tornado Spin (6 - 1 SP from TS mastery book)
80: +3 Tornado Spin (9)
81: +3 Tornado Spin (12)
82: +3 Tornado Spin (15)
83: +3 Tornado Spin (18)
84: +2 Tornado Spin (20), +1 Mirror Image (12)
85: +3 Mirror Image (15)
86: +3 Mirror Image (18)
87: +3 Mirror Image (21)
88: +3 Mirror Image (24)
89: +3 Mirror Image (27)
90: +3 Mirror Image (30)
91: +3 Flash Jump (12)
92: +3 Flash Jump (15)
93: +3 Flash Jump (18)
94: +2 Flash Jump (20), +1 Owl Spirit (1)
95: +3 Owl Spirit (4)
96: +3 Owl Spirit (7)
97: +3 Owl Spirit (10)
98: +3 Owl Spirit (13)
99: +3 Owl Spirit (16)
100: +3 Owl Spirit (19)
101: +1 Owl Spirit (20), +2 Nimble Body (2)
102: +3 Nimble Body (5)
103: +3 Nimble Body (8)
104: +3 Nimble Body (11)
105: +3 Nimble Body (14)
106: +3 Nimble Body (17)
107: +2 Nimble Body (19), +1 Flash Bang (1)
108: +3 Flash Bang (4)
109: +3 Flash Bang (7)
110: +3 Flash Bang (10)
111: +3 Flash Bang (13)
112: +3 Flash Bang (16)
113: +3 Flash Bang (19)
114: +1 Flash Bang (20), +2 Advanced Dark Sight (2)
115: +3 Advanced Dark Sight (5)
116: +3 Advanced Dark Sight (8)
117: +3 Advanced Dark Sight (11)
118: +3 Advanced Dark Sight (14)
119: +3 Advanced Dark Sight (17)
120: +3 Advanced Dark Sight (20)

Skills so far:
Dark Sight: 20 (max)
Disorder: 3
Double Stab: 10
Nimble Body: 19
Katara Mastery: 19
Triple Stab: 10 (max)
Katara Booster: 16
Endure: 0
Self-Haste: 20 (max)
Fatal Blow: 20 (max)
Slash Storm: 20 (max)
Tornado Spin: 20 (max)
Flash Bang: 20 (max)
Flash Jump: 20 (max)
Bloody Storm: 10 (max)
Advanced Dark Sight: 20 (max)
Mirror Image: 30 (max)
Owl Spirit: 20 (max)
Upper Stab: 20 (max)
Flying Assaulter: 20 (max)


Reasoning for this build: We max Flying assault and Bloody storm first as this skill combo are often used in training where we call it FABS. This FABS combo allow us to drag the monster together and use upper stab or triple stab on them. Upper stab is the better melee attack that triple stab, so you could forget about triple stab once you max upper stab. Putting skill points on mirror image allows you to do double damage so it seems like a common sense to pump it on lvl 70. Tornado spin allow you to do the FATSUS combo where instead of doing bloody storm after you push the mob with flying assault, you do tornado spin to push the mobs further. Advance dark sight isn't a must to max early on as it not really very useful for training but bossing.

Dual Blade Skills
Maple Warrior(30): Increase stats by a certain percentage for everyone in the party.
Venom(30): Smear your Katara with venom. Stacks up to three times. This cannot make the enemy's HP fall below 1.
Final Cut(30): Charge up your power to launch a huge attack on your foes.
Monster Bomb(30): Throw a sticky bomb which attaches to one of your enemies. After a short duration, it explodes causing damage to all mobs surrounding the bomb.
Sudden Raid(30): Attack all monsters on the screen for huge amounts of damage
Chains of Hell(30): While in Dark Sight, fling a chain in front of you to attach it to a monster. Pull it close to you, and then attack your opponent 12 times.
Stack Effect(30): Summons your other self for a certain amount of time. While your other self is around, the monsters will attack it, not you
Thorns(30): Provides certain party members an ability to locate the enemy's weakness, and in turn inflict lethal damage by exploiting it.
Hero’s Will(5): Guard yourself from a particular state. The higher the level, the more states you can stay away from.

Skill build
120: +1 Thorns (1), +1 Final Cut (1), +1 Sudden Raid (1)
121: +2 Thorns (3), +1 Venom (1)
122: +3 Thorns (6)
123: +3 Thorns (9)
124: +3 Thorns (12)
125: +3 Thorns (15)
126: +3 Thorns (18)
127: +3 Thorns (21)
128: +3 Thorns (24)
129: +3 Thorns (27)
130: +3 Thorns (30)
131: +3 Stack Effect (3)
132: +3 Stack Effect (6)
133: +3 Stack Effect (9)
134: +3 Stack Effect (12)
135: +3 Stack Effect (15)
136: +3 Stack Effect (18)
137: +3 Stack Effect (21)
138: +3 Stack Effect (24)
139: +2 Stack Effect (26), +1 Chains of Hell (1)
140: +3 Chains of Hell (4)
141: +3 Chains of Hell (7)
142: +3 Chains of Hell (10)
143: +3 Chains of Hell (13)
144: +3 Chains of Hell (16)
145: +3 Chains of Hell (19)
146: +3 Chains of Hell (22)
147: +3 Chains of Hell (25)
148: +3 Chains of Hell (28)
149: +2 Chains of Hell (30), +1 Final Cut (2)
150: +3 Final Cut (5)
151: +3 Final Cut (8)
152: +3 Final Cut (11)
153: +3 Final Cut (14)
154: +3 Final Cut (17)
155: +3 Final Cut (20)
156: +3 Final Cut (23)
157: +3 Final Cut (26)
158: +3 Final Cut (29)
159: +1 Final Cut (30), +2 Maple Warrior (2)
160: +3 Maple Warrior (5)
161: +3 Maple Warrior (8)
162: +3 Maple Warrior (11)
163: +3 Maple Warrior (14)
164: +3 Maple Warrior (17)
165: +3 Maple Warrior (20)
166: +3 Maple Warrior (23)
167: +3 Maple Warrior (26)
168: +3 Maple Warrior (29)

After that it doesn’t really matter what you put your SP into.

Reasoning for this build: This build, gives you everything you need for partying, training and bossing. Since 95% of our training skills have been maxed out in 3rd job+, Thorns is to improve training, this also makes every class except Sins and Archers want us, after that get Stack Effect to 26 for that 90 second timer which will be able to protect yourself, then max out CoH which gives us a ultimate weapon against any boss. Then max out Final Cut and Maple Warrior to make your damage better and make monsters fall to there knee's faster. If you want to have a quick training build, then you should max out sudden raid first then followed by the skills build i recommend. 


Credits - http://www.basilmarket.com/MapleStory-Guide-Ultimate-Dual-Blade-guide-314.html
And me for the edits.