Oh yeah, Spidey never removed his codex, he decided to go last just make sure everyone else's was removed, but then Kletus showed up...
Wonder if Knull can use just a codex is enough to control someone, at least temporarily, since they tend to disappear after a while when they're used.
And honestly, it was kinda weird that the Venom symbiote was trying to say that it wasn't Spidey's responsibility for bringing symbiotes to Earth, so Spidey doesn't feel guilty anymore, 'cause yes, while it's true that Grendel and whatever else were on Earth for hundreds or thousands of years, it was Venom and his offsprings who made so many people getting codice to begin with, so Spidey still has reasons to blame himself for Absolute Carnage, and King in Black, even if he's not the first one to have brought symbiotes to Earth.