Any Sin expect Diane can solo him. NnT get a decide feat last chapter speedwise. They gonna burst Natsu, I would even put the 7DS above the whole Fairy tail guild at their current states. Probably it can change after we get more feats from 100years quest.
@skysanji: if diane is around base Mel physically than realistically she's far beyond Natsu. Her golems give her a lot of versatility, her durability is top notch, and she hits in that multi-mountain range.