What I do is I use-Pyrus Elfin 400, 500, 700GAquos Fencer 700GHaos Mega Brontes 700GI just try to use brute force and for those cards like Duck and Win I just hope my Elfin gets weak....
Maybe list some cards as well? BTW witht hat strategy it might be good to use the E series Rainbow with your Fencer as you'll get a 200 G-Power boost from the bonuses THEN an extra 150 G-Power for having 3 different Bakugan attribtues.