Dense Blue Mist (Blue)

Attacks that target you this turn get -1

.

If a Chi was pitched to play this, effects don't trigger if an attack hits you this turn.

This prevents any effect that would trigger if an attack hits, including on-hit and on-damage effects. It does not prevent effects from triggering if the attack deals damage in other ways (in steps other than the damage step of combat), nor does it prevent effects that check if attacks previously hit (eg. wager).
If an effect would trigger, but is prevented by this, it still counts towards the number of times it would trigger. For effects that say “The next time” or “The first time” that are prevented from triggering, they won’t trigger again because their conditions were already satisfied.
To meet the condition “If a Chi was pitched to play this”, you must actively pitch a card with the Chi subtype to play the card. Using (chi points) to pay the resource cost for this does not meet this condition.