[Question] New Terrain Effect

So I'm creating a new Terrain called Shadow Terrain which is set up by the ability of an Evil Legendary Pokemon. I have 2 ideas for the effect of the Terrain, but I don't know which one to pick. So which of these effects is better?

1. Increased Critical Hit Ratio of all Dragon type Moves by 1 stage.
   Prevents Confusion.
   Sets Up Magic Room effect.
   If any Pokemon is OHKOed then it survives and regenerates all HP.
   
   
2. Boosts damage of all Dragon type Moves by 30%.
   Sets up Heal Block Effect.
   If any Pokemon is fainted with super effective or critical hit, then the fainted Pokemon brings down the attacker with it.

the 2nd one please. it sounds so evil.
just make sure it doesn't work on both sides.
otherwise the legendary will faint too, if it kills one of the player's pokemon