User blog comment:IamJakuhoRaikoben/Chapter 371: Tartarus Arc: Part 2 - Song of the Heavenly Dragon, Review./@comment-17764746-20140215003647/@comment-173.79.102.70-20140215022446

It's seems to have been a little while since the last torture session, and Erza's ridiculously durable. And Kyouka seems to be relying on her curse to avoid the need to inflict real damage. It's not like she blinded one of Erza's eye's like the last batch to torture her.

The Tartarus castle doesn't seem that heavily populated. So it shouldn't be that difficult for Natsu and Lisanna to avoid running into anyone of consequence on their way to Erza. The bomb being activated just means it was counting down, not seconds from exploding. A couple of minutes would suffice for what Cana did. Also it's pretty clear there was some passage of time between Face being unsealed and the accompanying shaking that gave Natsu and Lisanna the chance to escape, and their arrival at Fairy Tail.

Natsu's never been shown sick on flying things, and a floating island is larger than anything he's been on.

They waited for Kyouka because they'd be sure to be able to ambush one member of Tartaros, and could possibly force the location of Mirajane out of her rather than stumble around the castle looking for her and getting ambushed themselves.

All told, most of Tartarus has been pretty competent, as long as you aren't defining "competent" as "one-shots their opponent". The only one to drop the ball is Kyouka who opted to torture a resistant Erza rather than have Sayla easily force answers out of her, and who rushed to kill Crawford the moment he became a key instead of waiting the short time to transfer it to a prisoner and keep Crawford around until they had used Face and definitely no longer needed him.

As other people pointed out, the title for this chapter is clearly intended to be for the next several chapters, the way the title for "Tartaros arc part 1" was.

The other guilds have apparently been helping out off panel to check on other former councilmen. If there'd been more time it might have been worthwhile to summon them for the attack, but they ended up being forced into a spur of the moment attackwhich kind of precludes calling their allies to join them before heading out.