Fairy Tail Series 2 Episode 70: Tartaros Chapter: Hell`s Core
Episode 70 of 102 of Fairy Tail Series 2, aired August 7, 2015, 25 minutes. Available with English subtitles and dub where released.
Episode summary
While Franmalth attempts to absorb Natsu and Lucy's souls, Mirajane discovers the secret to the demons' immortality in Hell's Core, right before Seilah unleashes the restraints on her own power to take on Mira.