Forum:Prohibition - Big Question

Alright, so me and my friend were dueling, and he summoned a monster (Tri-Horned, for what it's worth.) I ended up destroying it, and re-summoning it on my side with monster reborn. I then used prohibition on it.

Question 1: What should happen to the monster, and should it still remain unaffected after being destroyed?

Question 2: Can I use prohibition on it while it's on the field?