User blog comment:B214/Chapter 499: Gray & Juvia/@comment-4933386-20160829110259/@comment-7418318-20160829142057

It would have been nice (okay not exactly nice, but less annoying) if it had been "a few" chapters instead of just two between Gajeel's "death" and revival.

But at least there was a good reason why he was kept from dying, with him being teleported within the life-preserving arua of the Tree before actually succumbing.

Here with Juvia it's a bit different, since at least her body is already dead. Not close to dying and beyond conventional healing, but already dead. Otherwise the chain wouldn't have disappeared.