Well you have to think, not many Naruto characters could even get past Naraku's most basic defense. The wind scar was said to have the power to shatter mountains, and Naraku's normal barrier that he always has on wasn't even scratched by it. The red wind scar broke it fairly easily, but other than that, there's no real gauge of how strong Naraku's barrier is, other than it must have at least mountain range+ durability. Also, Naraku has some pretty godly powers, and said that even the dragon guy that Inuyasha's dad fought was fodder to his power.
Sesshomaru was arguably less than or equal to that dragon guy(I can't remember his name, I haven't seen Inuyasha in a while), and he destroyed an entire forest with one attack. Other than that and Naraku's hax godly abilities like creating servants like kana who can deflect and block any attack, his mind control and regeneration, he doesn't have too many feats or even statements. Worse comes to worse though, he summons a black hole and the cast of Naruto gets sucked in.
He still stomps imo. Plus he can teleport, fly, summon millions of demons, use miasma to poison anyone instantly, and plenty of other techniques and abilities that would let him counter just about anything Naruto and company could muster. A great fight though would probably be him vs Jyuubito or the Rikudo sennin, although neither of them have many feats either...