How will we know if we are facing an upgrade boost / Lt?Must our opponent declare before the match, and we decide at that moment whether to pay or not?
For the event card: how are these upgrades distributed? Our opponents' deck is unknown to us as is the number of upgrades. Can we upgrade extra cards after deckbuilding ends: is an announcement made towards those choosing to use the event card as to how many cards they may upgrade in their deck? And do these upgrades still need to have at least 4 in element?
We suggest that you build your soldier decks as regular (8 upgrades), and then add in the extra upgrades at the start of the duel phase if you want to use the event card. Yes there will still need to be at least 4 in-element upgrades in your deck.
Are the upgrades from EC free, or are they locked in? In other words, can they be shifted around in the deck?