The Quickening system is much like a slot machine, so there's some luck involved. As the initial attack occurs, up to three lines of text appear in the bottom-right corner of the screen, one line for each character participating in the attack. Think of these lines as the WHEELS of the slot machine.
The "wheels" randomly cycle through four possible outcomes. They will display the name of a character's level 1, level 2, or level 3 Quickening or the words "Mist Charge". When they appear in white, the player can activate the command by pressing the button shown to the left of the line text. NOTE: that lines appearing gray in color aren't available.
With a little luck, there will be a white line or two available from which to choose, but eventually three gray lines will appear. Press the R2 button when this occurs to shuffle the commands again in hopes of getting a white line or two.
The player can initiate as many attacks as possible withing the four second time limit. By achieving certain attack combinations, the party unleashes a powerful Concurrence that delivers a devastating Final Hit to the target and any nearby enemies. So what makes the white and gray lines appear?
There are 8 Concurrences. If you don't know what a Concurrence is then let me explain. Think of it as a Final Blow after you're done with all your Chained Mist Quickenings. Concurrences aren't "automatic". You will need to trigger them via certain conditions.
Requirements:
Black Hole: 4 lvl 1Quickenings, 4 lvl 2 Quickenings, 4 lvl 3 Quickenings
Whiteout: 3 lvl 1 Quickenings, 3 lvl 2 Quickenings, 3 lvl 3 Quickenings
Ark Blast: 2 lvl 1 Quickenings, 2 lvl 2 Quickenings, 2 lvl 3 Quickenings
Luminescence: 5 lvl 3 Quickenings
Windburst: 5 lvl 2 Quickenings
Torrent: 2 lvl 1 Quickenings, 3 lvl 2 Quickenings
Cataclysm: 7 lvl 1 Quickenings
Inferno: 3 lvl 1 Quickenings