- If your opponent has "Necrovalley" and you activate "Madolche Chateau", the "Shuffle all "Madolche" monsters in your Graveyard into the Deck." effect is negated, but "Madolche Chateau" remains on the Field Zone. Furthermore, even if the effect of the opponent's "Necrovalley" is being applied, since the "If a monster(s) in your Graveyard would be returned to the Deck by the effect of a "Madolche" monster, you can add it to your hand instead." effect of "Madolche Chateau" does not affect cards in the Graveyard, that effect is applied normally.
- Even if there are no "Madolche" monsters in the Graveyard when "Madolche Chateau" is activated, if there are "Madolche" monsters in the Graveyard when the effect resolves, they are returned to the Deck by the effect of "Madolche Chateau".