So in HoA, we learn that the mist spirit that had been following Vin and tried to kill Elend at the well was what remained of Preservation’s consciousness.

We know he tried to kill Elend so that Vin would use the power to save him, rather than releasing the power (and therefore releasing Ruin). But it was established that Preservation is incapable of killing like that, because it’s an inherently destructive action.

I’d argue that it was a loophole in that he did so in order to preserve the world as a whole, but that same stipulation is why Ruin had to be imprisoned, because destroying it outright to save the world was impossible because of Preservation’s nature.

Am I missing something, or was this a contradiction of Preservation’s nature.