Wanting to experience the at home overpowered matches

Getting back into the game I cannot really remember how power scale and what not works and I believe it has changed over time with updates but I’m not too sure. My friends and I want to set up the game so that when we play there is a noticeable difference in damage and what not based on how strong that character is. I am not sure if this is an option or if that’s how it automatically is but trying to figure it out. When we sit down to play besides style points is there any benefit from transformations, like does the character get stronger compared to their base form or is it just new abilities and skill?