I second the notion of going for skillbreaking kurenai. The chaos chase is ridiculously helpful.

My team that I had some fun with was

x Sage naruto X

Kurenai Water Main Roshi,

x x x

But you can probably supplement roshi for kimimaru and sage naruto with normal naruto and frog summon. The reason it worked well is because the tank gets a lot of support from having a debuff reflected off of them because of kurenai and heals, but then naruto can start a combo and end up with that target being chaosed round 2, or if you cheese and skillbreak kurenai's basic attack to chaos. Focusing down whatever seems to be an issue right away usually does the trick, such as multi attackers and damaging mysteries.

As for battle power, I'm going to take a shot in the dark and suggest you start hammering those brothers team instances, thats how I went from the high 40s to mid 50s over a few weeks.