Here, the power is ranked by how powerful they are in POT, not whether any of these techniques would have their intended effect in real life.
1. Phoenix of Egypt (Byodoin), Meteor Lob (Niou, in a dream)
As far as I can tell, both shots involve hitting the ball really really high.
I wont ask for a specific number..since not a lot of characters have special serves
1-Tannhauser-it's just lovely really
2-Twist serve-for a 4'11 12 year old to hit a kicker with that much kick (it flies about 7 feet in the air) is ridiculous and awesome
3-Waterfall serve/Scud serve-They are...