Helzephyr – Wings of the Moonless Night

What is night?

This is a game state that changes via card effects. Being "night" does not inherently trigger any rules by itself, but certain cards have abilities that activate or become active while it is night. Additionally, if either player changes the state to night, the abilities of both players that become active while it is night become active for that duration.

Does an 【On Deploy】 ability activate even if the card is deployed from a zone other than the hand?

Yes, it activates. The 【On Deploy】 ability activates not only when deployed from the hand, but also when deployed from the deck, graveyard, or other zones by card effects.

With an ability that states "Choose up to X cards," can I choose 0 cards?

Yes, you can. Even if there are eligible cards to choose, by choosing 0 cards, you can effectively choose not to select any.

Does the ability 〈【AUTO】 When your Pal with 〈Nocturnal〉 is deployed〉 of BP01-073 《Helzephyr – Wings of the Moonless Night》 activate when 《Helzephyr – Wings of the Moonless Night》 itself is deployed?ますか？

Yes, it activates. Since 《Helzephyr – Wings of the Moonless Night》 itself possesses 〈Nocturnal〉, its 【AUTO】 ability activates when it is deployed.

I put a Pal into the graveyard using the 【AUTO】 ability of BP01-073 《Helzephyr – Wings of the Moonless Night》. If this card is already in the rest state at the end of the turn, how should the clause 〈If 1 or more cards were put [into the graveyard], rest this card at the end of that turn〉 be resolved?

If it is in the rest state at the end of the turn, nothing in particular happens because it is already rested. Since a Pal in the rest state cannot become rested again, the resolution finishes without any change.

I have BP01-073 《Helzephyr – Wings of the Moonless Night》 and BP01-088 《Lamp》 in my base, and the game state is night. If one of my Pals that does not have 〈Nocturnal〉 is deployed, can I put a Pal into the graveyard using the 【AUTO】 ability of 《Helzephyr – Wings of the Moonless Night》?

Yes, you can put it into the graveyard. Even if a Pal originally lacks 〈Nocturnal〉, it gains 〈Nocturnal〉 through the ability of 《Lamp》, allowing you to put a Pal into the graveyard with the 【AUTO】 ability of 《Helzephyr – Wings of the Moonless Night》.