Blade And Soul Assassins are quite literally gods

Assassins are, undoubtedly, the top tier class in PvE, and among the high tier classes in PvP. They are actually not "all just about" damage and offensive buffs, they possess largest and most useful utility kit overall than any other class, and it's their job to properly manage their tools for the right situation. Now, what do we have in our toolkit?

Melee "Offensive jack-of-all-trades"

Highest damage in the game alongside Force Master

Group mob bypass via stealth and taxi pull

Anti-projectile field

Double hit group invincibility frame via stealth protection (required in future dungeons)

100 meter downed party rescue pull affecting all formed of downed states

Effective bleed stacker (-20% natural HP regeneration, stacks up to 5 times)

Group buff via Fighting Spirit (40% crit rate + 50% crit damage + 70% life drain)

Grab restraint (albeit the worst one out of all classes)

Knockup extension (huge boon in future dungeons)

Assassins are extremely versatile, with the ability to protect our party members from harm via a stealth invincibility frame and an anti-projectile field, as well as transporting them through lethal trash mobs, and rescuing stragglers who end up dying to trash without needing to engage them. Their trademark solo stealth is remarkable; while most bosses in the endgame can see Assassins through stealth, trash mobs and minibosses still cannot, allowing for safe dispatching while every other class attracts everything and everyone and potentially ends up dying. Finally, we are most notable for buffing the party, as well as stacking bleed debuffs on the boss so they cannot regenerate health in the millions.

The main downsides, however, are their lack of area of effect skills (which rarely matter in most situations), a sub-par grab with very wonky activation conditions (though still useful if there's no other grab class in the group), and an extremely high learning curve; our ability to use stealth and stack poison rely on specific conditions (e.g. target's back, if target is poisoned, etc.) and in certain situations some or none of the conditions can be met.

Overall, Assassins are quite literally gods, covering almost every angle and filling in gaps of the capabilities of other classes, and are practically required in the future content, but are one of the most difficult classes to master. If you want to be both useful to the party and endure challenge, along with the perks of stealth, this class is for you.