Quote

I'm looking at the combination of Under Siege and Chukan Nobue, and I'm curious about the interaction between the two of them.
The discard in Under Siege appears to be a delayed effect. When looking at delayed effects in the rules, there's a line: "When a delayed effect resolves, it is not treated as a new triggered ability, even if the delayed effect was originally created by a triggered ability"
Chukan Nobue stops "abilities triggered by your opponent" from discarding cards in your hand. I have no idea how to put this all together, but it sounds like you would still discard your hand from an opponent's Under Siege due to the sentence above since it's a delayed effect and no longer a triggered ability.

The rule you’re quoting hinges around the word “new:” a delayed effect created by a triggered ability is still considered to be a triggered ability, but it is not a new triggered ability. It is an extension of the triggered ability that originally created the delayed effect.
Therefore, Chukan Nobue does prevent her controller from discarding the cards drawn by an opponent’s Under Siege.

[Tyler Parrott, Jun 29 2020]

Quote

Thanks for the answer. Out of curiosity, if Chukan Nobue enters play during the conflict, will she still prevent the delayed effect from discarding cards?

Chukan Nobue will prevent the delayed effect from discarding cards if she enters play during the conflict.

[Tyler Parrott, Jul 12 2020]