In the village of Lanuevo, activate the quest where you must get the Senastille and Kongsun couple together. When you find the father of the Kongsun woman, talk to him repeatedly to keep gaining points.
First open up Explorer and navigate to your saved games folder. Open the folder that contains the saved game you're currently playing and look for a file called "global.gs". Open it up with notepad and search for the following strings
(Note: replace any number after the string to indicate the level of your chakra
skill. The max level for any skill is 4, so don't go above that or it'll get bugged).
Change "skill_level_red0" to "skill_level_red4" in order to get level 4 Combo skill.
skill_level_brown0 Attack Dmg +%
skill_level_brown1 Attack Dmg +%
skill_level_brown2 Attack Dmg +%
skill_level_brown3 Attack Dmg +%