With a (SHADE) character card in my battle zone and Searching ! in set zone C, I set a character card that isn't (SHADE) while preparing for the turn. This turn, can I use the effect of a (SHADE) character card in my power charger with Searching !'s effect?
A
Yes, you can. If you swapped out a (SHADE) character this turn, Searching !'s effect can take effect even if the character card put in the battle zone by the swap isn't a (SHADE) character card.
With a (SHADE) character card in my battle zone and Searching ! in set zone C, I set a (SHADE) character card while preparing for the turn. If my opponent is the priority player and set NIRA-CHAN (Hippocampal Pain), does Searching !'s effect take effect?
A
Yes, it does. The fact that you swapped in a (SHADE) character card that turn remains, so Searching !'s effect can use the effect of a (SHADE) character card in your power charger.
I ended a turn with power cost 4 in my power charger, KAITO-INC-NEKO (SHADE) in my battle zone and Searching ! in set zone C. Next turn I set NIRA-CHAN (SHADE) and swapped characters. The power cost of the character in my battle zone isn't met, but can Searching !'s effect take effect?
A
Yes, it can. In this case the condition of the effect of the (SHADE) character card Searching ! can choose ("If you swapped in a (SHADE) character this turn") is met, so the effect of the card chosen with Searching ! can take effect.
Is the condition "If you swapped in a (SHADE) character this turn" on (SHADE) characters' effects met when they're swapped by my opponent's NIRA-CHAN (Hippocampal Pain)?
A
No, the condition isn't met in that case. "If you swapped in a (SHADE) character this turn" means when you did the swap yourself. So even if your character card was swapped by NIRA-CHAN (Hippocampal Pain), effects with the condition "If you swapped in a (SHADE) character this turn" can't take effect unless you swapped in a (SHADE) character yourself this turn.
When using Patchwork notes, can I choose not to reveal my hand?
A
No, you can't choose not to reveal your hand. You can't choose not to use an effect that can take effect (its power cost is met and its conditions are met), so while its power cost is met you have to reveal your hand, even if you don't have 4 or more elements in your hand or don't want to reveal it.
in set zone C, I set a character card that isn't (SHADE) while preparing for the turn.
