Each folk has its own karma and by releasing it, the folk's abilities will improve.
Each folk has a table listing the things that need to be done to release karma. To view this table press 
and use the arrow keys to find the folk you want to see the details for, now press 
two times. It usually requires you to absorb the Id of folks, defeat folks or use some Karma Release Items. You must manually use items by selecting the table row and pressing , of course this will not work if you don't have enough of an item.
Some of the abilities that can improve are;
- MC consumption lowered
- Attack Power increased
- Effect Area increased
- Ammo increased
- Charge Level + 1
- Consecutive Use+ 1
- Simultaneous use + 1
- Combination Attack + 1