MapleStory/Thunder Breaker/Builds

AP build
It is best to add all your points into STR. Luckily, the Auto-Assign can do that.

First Job
First, add 1 point into all 4 skills: Lightning Punch, Flash, Lightning Element, and Electrified. Max Lighting Element first for the extra duration, chance for Lightning Buff, and amount of defense ignored with the Lightning Buff. 1 point into your attack skills should suffice for now. Afterward, max Electrified for the speed and jump boost and the additional Lightning Buff chance. Next, raise Lightning Punch to 19, since it's hardly used after 1st job. Finally, max Flash. Neither skill is used much later on, so you can feel free to max Lightning Punch instead of Flash.
 * Skills:
 * Lightning Punch (20)
 * Flash (20)
 * Lightning Element (20)
 * Electrified (20)
 * Optimal build

Note, for the skill tables, the numbers are listed respectively. For example: Lightning Punch, Flash|1, 2|19, 3| means Lightning Punch has 1 SP added, totaling to 19, and Flash has 2 SP added, totaling to 3.

Second Job
First, you'll want to add 1 point into Shark Sweep (a new attack skill), Tidal Crash (a rush skill), Knuckle Mastery (stability), and Lightning Boost (for the extra Lightning Buff stack and 1 Weapon Attack). Ideally, you'll want to max Mastery first to have more stable damage. When you get to 5 Mastery, add 6 points into Booster to have two minutes of increased attack speed. Next, max Mastery, and then Booster. Afterwards, max Lightning Boost for the extra Lightning Buff chance and Weapon Attack. Next, max Gains for extra strength. Now it's up to you whether or not you want to max Shark Sweep or Tidal Crash, but it's recommended to max Tidal Crash for more utility.
 * Skills:
 * Shark Sweep (20)
 * Tidal Crash (20)
 * Knuckle Mastery (10)
 * Knuckle Booster (10)
 * Gains (15)
 * Lightning Boost (20)
 * Optimal build

Third Job
Congratulations on 3rd job! Once you receive it, you'll want to add 1 point into Ascension, Thunder, Gale, and Lightning Lord. With Ascension and Thunder, you receive a new training style. Gale gives you a nice damage increase for every accumulated Lightning Buff. Lightning Lord gives an additional 11 Weapon Attack at level 1, and gives you an additional Lightning Buff to accumulate (total: 4 now), as well as the rate of accumulating it. First, you'll want to max Lightning Lord for the extra weapon attack and Lightning Buff chance. Next, you'll want to max Link Mastery for the extra damage dealt from linking skills. Afterward, you'll want to max Ironclad for the 10% damage reduction and 5% extra damage. Next, you get to decide whether to max Ascension and leave Thunder at 14, or vice versa. After, max Gale for the damage boost from accumulated Lightning Buffs (note, it MUST be maxed for Typhoon in 4th job), and finally, Seawall must be maxed for extra Status and Elemental Resistance. Note: Alternatively, you could leave both Ascension and Thunder at 17.
 * Skills:
 * Ascension (20)
 * Thunder (20)
 * Gale (20)
 * Seawall (20)
 * Ironclad (10)
 * Link Mastery (20)
 * Lightning Lord (20)
 * Optimal build

Fourth Job
Congratulations on triple digits! First things first, you'll want to add 1 point into Annihilate (1v1 attack skill), Thunderbolt (new mobbing skill), Typhoon (upgrade to Gale), and Speed Infusion (additional attack speed). Next level, you'll want 1 point into Knuckle Expert, Thunder God, and Arc Charger. You'll want to max Arc Charger first, which is like Shadow Partner, increasing your number of hits with the extra hits doing 40% of your normal damage. Next, you'll want to max Knuckle Expert for the extra Mastery, Weapon Attack, and Minimum Critical Damage. After, you'll want to max Thunder God for an additional Lightning Buff accumulation (total: 5 now), as well as chance to activate it, Critical Rate, and Maximum Critical Damage. Afterwards, you'll want to max Typhoon for the additional damage boost. Afterwards, max Thunderbolt for additional mobbing damage. At level 150, when you obtain the Hyper Skill Primal Bolt, you can spam Typhoon, allowing for amazing mobbing ability by linking Thunderbolt and Typhoon. Next, max Electrify for the extra HP, avoidability, and damage reduction. Now, max Annihilate as your 1v1 skill. After, max Call of Cygnus (Cygnus Knight equivalent to Maple Warrior), and finally, max Speed Infusion (or leave it at 10 so it stays in sync with Booster. It's your choice).
 * Skills:
 * Call of Cygnus (30) (UNLOCKED AT LEVEL 120 VIA QUEST)
 * Annihilate (30)
 * Thunderbolt (30)
 * Typhoon (30)
 * Arc Charger (30)
 * Speed Infusion (20)
 * Knuckle Expert (30)
 * Electrify (10)
 * Thunder God (30)
 * Optimal build