I just noticed something now that the first treasure-attack exists. The general rule with attack cards and
Moat is that "whenever another player plays an attack card" happens before the instructions on the played card are followed. But that's more awkward with
Relic. Relic says "when you play this". Moat says "whenever another player plays an attack card". As worded, this is 2 events that trigger at the same time, and under normal rules for dealing with that, the effects would be dealt with in turn order. So effect from the person playing Relic would happen first, giving the -1 card token, and THEN the effect from Moat would happen, allowing the person to reveal Moat.
This isn't in the rules forum because I know the correct interaction here; Moat still works just fine. You reveal Moat and are protected from the attack before any of the card's instructions are followed. I don't think there's any confusion over that. I just thought it was a weird thing worth mentioning.