[quote=@Flamelord]
<Snipped quote by IncredibleBee>

Is it actually at that point yet though, or still in the 'setting up' phase? I haven't read the manga. 
[/quote]

The short answer is "Probably".

Guts' most recent kill in the story was the Sea God, so it's safe to assume the Dragonslayer is at or very close to anti-deity status at this point. Additionally, every kill on a magic being makes it stronger, so hypothetically he can kill anything after he kills enough things.