Timid Coronet
how do you deal with gravekeepers and their
necrovalley?
"All 'Gravekeeper's' monster gain 500 ATK and DEF. Cards in either player's Graveyard cannot be removed from play. Cards in either player's Graveyard cannot be affected by card effects,
except for their own effects."
^ That's how. Necrovalley only prevents other cards from returning them to the deck from the grave, but the Madolche monster actually have that listed in their effect.
"When this card is destroyed by your opponent and sent to the Graveyard: Shuffle it into your Deck."
The following rules apply to all Madolche monsters:
Returning this card to the Deck is a Compulsory Trigger Effect.
If this card is destroyed when its original owner does not have control of it, the effect does not activate.
The effect to return to the Deck when is destroyed by the opponent and sent to the Graveyard will activate even during the Damage Step. The effect will also activate even if is destroyed in battle by an opponent's monster.
This effect will activate even if this card is destroyed in the hand or Deck by the opponent and sent to the Graveyard.
If "Necrovalley" is active and "Madolche Mille-feuille" is destroyed by the opponent and sent to the Graveyard, the effect is not negated and the monster returns to the Deck.