Add a SuperBot Buu and set him to;
Move: No.
Shoot: No.
Ignore Human Players: Yes.
Then just melee him around the map for a while and your PL/CF will skyrocket. Melee is easily the fastest way of gaining PL, and the stronger your opponent is the more PL you gain when you damage them. Buu has the highest starting PL for any character and as a SuperBot will transform right away, allowing you to reap the rewards.
In an actual game you'll have to rely on meleeing moving opponents who'll hit you back so get some practice in and make sure the server allows transing first.