QuoteI play Common Cause, sacrificing my Chancellor's Aide to stand another character. I trigger the interrupt on the Aide and my opponent gives me an honour to make me discard. Can I discard the Common Cause? Will it continue to resolve? As a related question, when I play Command By Name can I discard the same Command By Name I'm playing as part of the cost? I think you shouldn't be able to but I can't see what stops you.
If you discard a card from your hand while the costs are being paid to play that card, the card can no longer initiate its effects in step 6, as it is no longer in your hand to complete the “Playing Cards” process.
[Tyler Parrott, Oct 9 2020]