Day 8;
In the morning move him to new soft water. (condition new water with dry banana leaf) 15 minutes after you have moved him to his new container, put a small female into his container for a minute. The male will flare and chase female around.
You must remove the female immediately if your fighter starts to bite her. This is to make your fighter active and fierce. Do this step again in the evening. Make sure he doesn't bite anything during training to protect his teeth for fighting!

Day 9-11;
Prepare a circle tank or at least 15" high bucket with a small aquarium water pump. Put 12" water high and put a small bottle with a female into the center of the males tank. Put your fighter into circle tank. He will swim around the female bottle to try to figtht the female.
Turn on the water pump to flow the water around tank. Your fighter will try to go against the water flow. Let him exercise like this for 15 minutes after feeding in the morning and evening. This will give your fighter a strong body and help him to develop good breathing techniques.

Day 12-13;
Let your fighter relax in his container. Repeat day 8 step once a day. Feed him only a little food in the evening.

Day 14 goto fight!
Feed the fighter a bit food in the morning. Do the step of day 9 for about 5 minutes by releasing the female into tank without water pump and bottle.

Notes! Please use your judgement before goto arena. The ready fighter must be very fierce. He will be very active and very aggressive to bite immediately when see other fish or your finger. Some fish will be full flare his gill and open mount for bite when see everything that look like fish although he is far from object.
Good Luck...