My question can litteraly be found in the errata/FAQ, but the given answer is still ambiguous.
Quoting the errata/FAQ:
Q: When exactly is the decision made to use the Valyrian Steel Blade’s ability to either draw a replacement Tides of Battle card or receive +1 combat strength?
A: If you are playing with Tides of Battle cards, there are two opportunities for a player to use his Valyrian Steel Blade:
1) "Choose and Reveal House card" step: After each side draws a Tides of Battle card, but before they are revealed, he may decide to use the blade to draw a replacement Tides of Battle card.
2) "Use Valyrian Steel Blade" step: If he has not used it yet this round, he may now decide to use the blade to add +1 to his combat strength.
The ambiguity is in the last sentence:
[...] he may now decide to use the blade [...]
Well, when is now? I understand that first you will have to decide whether or not you want to use the Blade to draw a replacement Tides of Battle card. You will decide this after you look at your drawn card, before it is revealed. OK so far. Let's say I choose not to use it. OK so I still can use the sword to get +1 combat point. But when, exactly?? Before or after I see my opponent's Tides of Battle card?