The FAQ does not answer the question of whether Blood Frenzy can be used without units already battling.

Q: Does the Khorne player need to have any of his figures in the same region as a Blood Frenzy card in order to roll the two battle dice granted by the card?

A: No. The Khorne player gains these battle dice from the card's effect, and does not need figures present to benefit from the card.

The answer only clarifies that he doesn't need his own units present. But my group argues that because the card itself says 'before battle, roll two dice', if there is no pre-existing battle condition (like someone else's attacking units, with valid targets such as a peasant), the card has no effect. I.e. Khorne could not use it to get 'free' two battle dice anywhere on the map with just this card alone - he'd have to ensure there is going to be a fight going on there, one way or another.

I think it's intended to give Khorne a way to cause damage even when people run away from him, but by strict reading the rules do seem to support my group's assertion. So, how would we get a clarified official answer to this?

Ah, now I found the link to mail FFG the question.

the card says you roll your battle dice before any other dice are rolled. it does not state that you role before battle. so this cards triggers a regular battle in a region with a valid target.

Turric4n said:

The card says: 'At the beginning of battle in this region, you roll two battle dice here and apply any resulting hits before regular battle dice are rolled'

It's that first part that's making it unclear. If there is no battle in the region, there is no 'beginning of battle', and that would mean this card has no effect. They could have said 'before resolving regular battle phase, roll two attack dice', but currently it's unclear.

Read the rest of the FAQ. It defines what a Battle is:

Q: During the Battle Phase, what
conditions trigger a battle in a region?

A: In any region where at least one player has an effect
allowing him to roll battle dice, and there is at least
one eligible target, there is a battle. Effects that allow a
player to roll battle dice may come from either a figure’s

attack value or a card effect. Eligible targets are player
figures and peasant tokens.

So its pretty clear that you have dice (from Blood Frenzy) and you have targets (from your opponents) so a Battle takes place.

Ah, it was defined. I somehow skipped over that, since it was at the bottom edge of a page... Well, don't I feel silly now.

Thanks for pointing it out. That should settle the issue.

Got an official reply to this one - Blood Frenzy always works, even if there's only one player/just a peasant token in that region and none of Khorne's/another player's figures.