Quickly shred high level enemies to pieces without even needing to equip the melee weapon and using a Covert Lethality finisher. A melee weapon that is proficient at quick melee complements players who prefer gunplay, with melee as backup.
The downside to daggers is their extremely short range. Thus, they are not suitable to taking down crowds, but are more than enough to mop up the leftovers of a shooting spree, or to take out that one tougher unit.
The build I use combines Stinging Thorn's excellent quick melee involving a 300% damage hit that guarantees a Slash proc with the high attack speed of a Zaw. Statuses are quickly applied to halve enemy HP with viral and to boost melee damage with Condition Overload. Combo counter is also quickly increased, allowing you to take advantage of mods like Blood Rush and Weeping Wounds immediately, even if only one enemy is being attacked.
As shown in the video, exchanging Covert Lethality for another mod like Blood Rush does increase damage, but I would not recommend it. There are times when, despite the high DPS of the dagger, Covert Lethality is preferred, like fighting Nox.