Okay, so I found this weird thing with Spinning Fire Blossom. If it doesn't hit an enemy, it won't cost you any Chi.
1. Use Expel Harm to get 2 Chi
2. Spam Spinning Fire Blossom into the wall or away from an enemy, as long as it doesn't hit anything/anyone.
3. Your 2 Chi's will refresh their duration everytime you use your Spinning Fire Blossom ability - even out of combat!
4. Use another Expel Harm to get your third and fourth Chi.
5. Keep spamming Fire Blossom until you pull boss and you will engage the boss with 4 Chi = massive dps increase!
It's also cool spamming it randomly in cities and when you're bored.