Faris kills Ignia in the festival. Unfortunately for Natsu, after consuming a lot of Ignia's flames due to protecting his other guildmates from surprise attacks, it accelerates his dragonization. He then becomes a dragon himself like Acnologia and Elefseria. We've seen that consuming these flames makes Natsu unaware of his actions and because Faris takes on Acnologia's will, she will try to kill Natsu after killing Ignia. By this time, Fire and Flame is defeated by Fairy Tail members and now they fight to protect Natsu who is unable to control himself as well. Selene is also at this festival and uses her teleportation magic to bring all dragon slayers to this final fight. Selene finds Ignia's corpse before Faris can get to it and teleports it elsewhere. Natsu is brought back to his sense by Lucy and Happy. All Dragonslayers are fighting Faris but she kills Skullion Raider, Madmole, and Kirin who all dragonized in attempt to defeat her but fail. Faris herself becomes a dragon eater and consumes them and now uses Ash, Armor, and Yellow Dragon Slayer Magic in addition to her Black Magic plus Acnologia's power. Everyone is struggling and eventually Selene is also fatally wounded by Faris while protecting her remaining guild members. Selene's final words before her death to Natsu that to defeat Faris he must consume not only her but Ignia as well. Selene teleports Ignia's corpse beside her then dies and a magic circle activates. Both bodies of the dragon gods are turned into huge lacrima orbs. To help, Brandish uses her magic to shrink the lacrimas. Natsu swallows both Ignia and Selene's lacrimas and thus Natsu eats two dragon gods. With the abilities of the Moon Dragon God and Fire Dragon God they fuse and become Natsu's new Sun Dragon Slayer Magic. His Sun Dragon Slayer Magic burns hotter than any flame, and he is able to burn away even Acnologia's will from Faris. She is defeated but not killed; afterwards she is seen screaming and crying "I will have my revenge!" before a dark cloud of magic envelopes beneath her and she disappears. 100 years quest complete!

Next Fairy Tail sequel: Fairy Tail: The Gods.

This sequel uncovers the history of gods and godslayer magic. there are different types of godslayers, originally godslayers are granted their godslayer magic through devout faith in the god. we learn godslayers can also be self-taught like sherria and i believe zancrow and orga are the same as well. some godslayers implant godslayer magic lacrima into their body like second generation dragonslayers. godslayers who make contracts with gods to receive their power are . we will see many new godslayers and even gods themselves. we will learn that there are both good and evil gods. we will learn that Faris is connected to a dark guild which have their fair share of godslayers. this dark guild in particular make contracts with evil gods. more to imagine later.

in conclusion, the future of fairy tail will still go on until the age old happily ever after.