Never ever use it on mobs that are unstunable. It has horrible DPS and damage and its only purpose is to give you a breather to pot in difficult places. It has an 8 second stun, which is the longest in Cabal, but it has a cast time to match it. Because of the cast time, it can work against you and get you killed rather than save your hide. If you're really low on health and need the mobs of your back for a second, it's better to cast a comp and down them instead of stigma. It also has a 360 range but no travel effect.
Force assault. Together with the next skill(cabal money) these are the trademarks of the FB class. It also has a travel effect, lunging you forward, towards your target at a limit 4. It's a single target skill, so don't use it in a crowd. It has good dps, especially when you get better gears and its native amp gets a boost. Best kept at level 20 for DoT and damage purposes.
Force slash. The other trademark FB skill. It has the same cast time as FA, but slightly more useful. It has a limit 2 and same DoT. The limit on the skill is rather strange. It's a right-hand skill, so if you place the mobs on your left, it won't work as good. Keep this in mind when you use it for the AoE. Also, at higher amp, it does slightly more damage. Same as above, level 20 is best.
Abyssal crystal. All sword classes have a ranged sword skill, but FBs is one of the most useful. It has a hit-rate debuff, which is close to useless, but it has a nice amp at lvl 20 and good DPS. Again level 20, max amp and added damage. Use our professional Cabal powerleveling service will make the game more funny.