I've been playing Rebellion for months and really enjoying this class. Most people think rebel is only an extend class, and ignore it, but it can be very powerful and helpful in instances and with MVPs. And of course, it's the best low/mid ti emb farmer.
I'm only aiming for Binding Trap and ASPD build for now. There are still many other powerful skills which I'm not familiar with yet. I hope I can try them and update later.
Builds (A little different from irowiki)
STR: 1-20 (for weight capacity, I recommend Gym pass since bullets and pots could be heavy)
AGI: 90-110 (depending on your gear and how much you're willing to spend on consumables)
VIT: 90-100 (for survival)
INT: 40-50
DEX: 120+ (for damage)
LUK: 33+
When leveling, put most points in DEX first since most rebel skills' damage depend on Dex. Don't need to rush AGI, Round Trip can push mobs back and has less cooldown time than Arrow Storm.
My low ti slave build:
STR: 20
AGI: 1
VIT: 50+
INT: 40
DEX: 110
LUK: 1
My mid ti slave(stay at 116) build:
STR: 20
AGI: 1
VIT: 50+
INT: 40
DEX: 120+
LUK: 1
Recommended Skills:
Rich's Coin: required for Round Trip and some buff skills
Platinum Altar: Increase ATK when using Siver or Purifying bullets. Reduce damage from undead. I recommend use Purifying bullets all the time when leveling. Use Element Converter instead of element bullets if damage not enough.
Binding Trap: Slow enemies and deal at least 15% damage of their current HP, 30% with AB's lex skill. Consumes 1 Special Alloy Trap each cast.
Flicker: Activate all Howling Mines and Binding Traps on screen. Has 10 seconds cooldown time.
Hit Barrel: Great boost for ASPD and ATK. Can't attack or use skills and itmes for 10 seconds when skill ends.
Gears:
Rebels can't equip Transcendent Class and 3rd Class gears, but there are still some options.
If only farm in low/mid ti, it is not necessary to get all best gears, I tried one shot everything in low ti without FAW.
Headgear:
Mid:
Low:
Armor:
Different element armor
Weapon:
Most gunslinger and rebel weapons can be bought from NPC or vending machine. And they are level 2 or 3 weapon, very easy to upgrade.
lvl 1-35 Eden or anyone has better idea, please let me know
lvl 100-106
Butcher[1] with Hillslion Card or Andre Card, can be obtained through a
quest
lvl 106-140
Minigun[2] with Archer Skeleton Card or racial cards for high ti
Garment:
Footwear:
Green Ferus Card or Firelock Soldier Card
Darklord Essence Concentration3
Accessories:

RWC Rings
Shadow:
Malicious Shadow Set for HP regan
Kingbird Shadow Set for damage
Though rebel is OP in low/mid ti, high ti could be a pain since mobs have high HP. I recommend use racial Minigun, Purifying bullets with element converters and DEX+20 foods. Rebels can do instances to level after lvl 120. Remember to bring an AB or Tank friend.
Instances:
Nightmarish Jitterbug: Round Trip on small mobs, Binding Trap and Flicker on jitterbugs, use Fire Rain between Flicker CD. Go with an AB for protection and Lex Aeterna.
Charleston Crisis: Round Trip on small mobs, Binding Trap and Flicker on Charleston 3. Also bring AB and fire armor.
Last Room: Need other party member to clear small mobs. Bring headgear with Nightmare Card and shield with Medusa Card. Use Binding Trap and Flicker on T_W_O, don't even need to eat strawberries.
Bakonawa Extermination: ASPD gears with CD in Mouth, fire armor and Costume Gold Dragonhelm. Bring Fireproof potion and Tikbalang Pet. Use skills adding ASPD mentioned above and Lightning Bullets and Bloody Shells.
That's basically all I know about Rebel now. I hope this helps. And this is my first time writing such a guide, if you have any good advice please let me know ^^