[quote=@chukklehed]
I haven't reached that far in the show yet, but I'm assuming that God Slayer magic is just like every other magic, it's only as strong as you can use it to be. Dragonslayer magic is supposed to be one of the strongest forms of lost magic, but Nathan could probably beat Sable down even without using his own magic.
[/quote]

Doubtful he'd be beating him while Sable is going all out with his magic and Nathan just going physical with none of his magic. That's going a bit far considering Sable is an A Rank. Not even Gildarts would attempt an all out fight with Natsu without using his magic.