If Frodo met Denathor....

[Numenorean]

Rutslegolas -

but would the ring ever corrupt or should i say take control of denethor because in denthor their was the blood of numenor

I get the feeling Denethor would have been corrupted rather swiftly by direct possession of the Ring. His Númenorean blood was fairly diluted anyway, his good spiritual faith had long since waned in favour of power politics, and as Eomer stated there are many instances where Númenoreans - even at the height of their dominion and vigour - were corrupted by the lesser rings and tricksy words of Sauron the Deceiver.