For effective use of non-hitscan weapons, it is strongly recommended to learn how to lead your target. In short, leading means aiming ahead of your target so the projectile still hits him. It can be a challenge to learn it, low level Grineer are recommended for practicing.
Despair daggers are affected by the mod Lethal Momentum, making it much easier to hit moving targets and longer range targets.
A "monofilament" is a type of wire or edge, consisting of a single strand or side of strongly bound together molecules. This creates an edge that is micron or even nanometer thin, the sharpest possible.
Typically, they are applied as a cutting tool or a weapon that can sever nearly any object or other molecules.
Organic molecular wires have been proposed for usage in optoelectronics.
Similarly to the Hikou and Kunai, the Despair is a secondary thrown weapon that deals mostly Puncture damage.