There’s only 1 build in the top 100 build ranking (Fencer > Matador > Barbarian) that involves Rapier-based classes, which completely goes against the philosophy of build variety in Tree of Savior.
Here are some class suggestions to allow for more freedom & uniqueness:
Rapier-based class that provides a wide variety of buffs due to their versatility and also works mounted.
Mount-based DPS Rapier class with a lot of AoE skills.
DPS Rapier class that works with Daggers & Shields as off-hand weapons with skills for both.
Mainly single target DPS that can fit in any Rapier based class build.