Quickening

Quickening increases the attack speed of melee weapons while channeling at the cost of reduced channeling efficiency.

Stats

Rank	Attack Speed	Channeling Efficiency	Cost	Conclave
0	+5%	-20%	6	C10
1	+10%	-40%	7	C10
2	+15%	-60%	8	C20
3	+20%	-80%	9	C30

You must be actively channeling the weapon for the speed increase (and energy penalty) to apply.
- Unlike other channeling mods, Quickening seems to activate as long as you have enough energy to channel, regardless of the channeling cost. Simply having Energy Siphon active on your team is enough to accomplish this.

At maximum rank, an 80% decrease in Channeling Efficiency translates to 4 additional energy for a total of 9 Energy per hit while Channeling.
With Fury, a maximum total of +50% bonus attack speed can be attained while Channeling.
- Combined with Berserker, this bonus attack speed can be increased to +140%.

Unlike most mods, the picture shows an Excalibur wearing the Pendragon helmet, his Immortal Skin, as well as a different color scheme. This is a rare instance of a mod depicting a non-default character loadout. The other examples are Life Strike, Second Wind, True Punishment, Enduring Strike, Warrior's Grip, Killing Blow and Corrupt Charge, all of which are channeling mods.
As of Update 15.5, there are four new mods that also depict non-default characters. These mods are Bore, Piercing Caliber, Breach Loader, and Auger Strike, all of which depict a Nyx Warframe with her Immortal Skin and Menticide helmet.