I was wondering id after declaring a blocker, one can give the blocker Shadow with either Dauthi Embrace or Dauthi Trapper and still have the block go through.

cant really understand what ur saying but if u mean

if one creature attacks and another bocks it and after declare blockers someone puts shadow on blocker.. attacker is still considered block and no damage is dealt since it is alrdy considered block regardless even if u destroyed the blocker after declare block phrase and before combat phrase.. attacker still is blocked

That's exactly what I meant. B)