, banish this card from your cemetery: Give each Knight on your field
+1 and Storm.
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Search your deck for a Queen Hemera the White and Queen Magnus the Black, summon them, then shuffle your deck. Give them +1/
+1.
QCan I choose to summon Queen Hemera the White but not Queen Magnus the Black, or vice versa?
AYes. Even if both are in your deck, you can choose to "not find" either or both of them.
QCan I only play this spell's activated ability when it's in my cemetery?
AYes, that's correct.