From the Blackest Night rulebook:

Okay, so, this came up at a tournament yesterday, and it got a ruling then. However, despite this ruling coming from Norm, I think it's wrong and I want to open a discussion here. Before I go any farther, I want to point out that I believe his ruling to make more sense and well.. better. However, given the wording in the book, I don't think it is correct.

The question is, how many times per tournament can this be done? The ruling was once. I think, based on the wording, it can be done every round. It never says "one per tournament" or "once per round" anywhere. It says when BFCs are revealed, you may choose to ignore one. It does not say how many times you can do this.

Now, I checked other places, but could not find any other distinctions other than this paragraph. If there is another location in the rulebook or player's guide that clarifies this, and I have missed it, I do apologize for that.

I also suppose I should clarify my reasoning for this thread, other than discussion, or I suppose I should clarify why I want the discussion. I only seek to have this corrected in future rulebooks or player's guides if I am right so there is no confusion.

it works kinda like outwit, you cant outwit someones imperv, attack them, then stop outwiting imperv, and say you use the same outwit to outwit a different power, you just cant...i know its totaly different ruleing, but its just an example

The rule book is not written for tournaments. The discussion of the theme team rules in the rule book gives no indication, one way or the other, as to how many time a BFC can be canceled (and note, it is canceled, not ignored like you say in your thread title) in a tournament. Just like the rule book doesn't tell you how many rounds should be in a standard tournament, or how to run a swiss pairing system. The rule book is concerned with the individual game itself, in a vaccuum.

If you want to know how tournaments operate, you need to consult the Comprehensive Tournament Rules:

2.3.2 Theme Teams: Theme teams may use their ability to cause all players to cancel a BFC once per tournament. Written notation should be made by the judge or opponent at the judge’s discretion as to which round this ability is used in. Other abilities granted by theme teams are not restricted in this way and may be used in each round subject to their normal restrictions.

(this
choice is made when battlefield conditions
are revealed) they're only revealed once, so the choice is only made once

Actually, in a tournament, they are revealed once per game, sure, but then if you've got 4 or 5 rounds in the tournament, that is 4 or 5 different times that they would be revealed. Hence the OP's question (and my answer above).

Thank you! See, that's what I meant when I said if it was somewhere else and I was just missing it.

I like that much, much better. Being able to ignore it every round felt way too powerful for my tastes.