Kurama Naruto isn't very scary in Arena from my experience although I am running a p2w Edo Deidara team. (Jinpachi, Shisui, Deidara, Fire/Earth) Neither is roshi unless you stack his stats with chases. If I went against that lineup in SWB I'd get my * kicked with such an offensive standard heavy team.

Shisui's mystery by itself is very good for that r2 chaos. If I am using fire main which I normally do, I use the fire style enhancement with 4 men standard and the fight is normally over by the time shisui uses mystery. Jinpachi and Deidara uses standard twice, shisui's standard damage isn't so bad, and fire main causes alot of damage with two standard with clone.

** forgot to mention shisui's barrier also boosts the fire units

*** I am also level 81 with a ini much higher than most people around my level. So I can't say how it will work against those much experienced/faster than I. However I have won against Kurama, Uchiha, dodge (Minato, MM, Edo tobirama) with this lineup

Of course, this only works in Arena as their stats are boosted Px