Hello there, VeryShae!
The Thing about Catharsis is that you have two fire modes. One, in which you gather power and the other in which you release it and harm the enemy base on how much power you had.
The gathering more is not supposed to do harm to the enemies, as you mention, as you are increasing the power bar. With the release mode, you can always hurt the enemy, there's no need to recharge it as you said, unless you want to increase the weapon's damage. That does create situations in which you need to change from one mode to another if you want sustained high power shots.