(SPOILER)The only time where a Quickening is forced is when Basch uses Fulminating Darkness on the Air Cutter Remora during Reks's portion of the game. But even that doesn't count...

Also, I use the Quickenings for two reasons:

1.) Watch the animations and see what Concurrence I can trigger.

2.) Get rid of a boss's minions.

Which brings me to this story...

(SPOILER)I was fighting Dr.Cid in the Draklor Laboratory, and I used a Quickening to wipe out his Rook minions, right?

Well, I triggered Black Hole, the strongest attack in the entire game (It can deal well over 60,000 damage to the primary target and substantial damage to any enemies around it!).

Anyways, Black Hole only killed one of the Rooks, while the other three were barely damaged (even though the Rooks only have 9,859 HP, which menas they should've been killed by the attack), and the attack barely dented Dr.Cid's HP bar.

I was so pissed! I still don't know what happened, but I can tell you that I let out all my frustration on Dr.Cid.