I find it easiest to be Shelby by Mp damage
Eguip Hammer of Might with Cliff as a long-range O
If you dont have it yet, level up until you do
When youre fighting him, use hammer of might once then run away so he cant hit you
then hit him again with hammer of might
and so on
if this works you should also get a battle trophy for beating him without taking damage
*Meet new friends but keep the old.
One is silver, the other is gold.*