702.145b Daybound is found on the front faces of some transforming double-faced cards and represents three static abilities. “Daybound” means [...] “As it becomes night, if this permanent is front face up, transform it,” [...]
702.145e Nightbound is found on the back faces of some transforming double-faced cards and represents two static abilities. “Nightbound” means “As it becomes day, if this permanent is back face up, transform it” [...]
702.145f Any time a player controls a permanent that is back face up with nightbound and it’s day, that player transforms that permanent. This happens immediately and isn’t a state-based action.
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Thus the permanent will transform (become front-face up), however, the copy effect will continue to apply in layer 1 and it's visible and copiable characteristics will be unchanged.
It will not try to transform again and again because 702.145f only applies to a back-face up bound-type TDFC. It will also not transform as it becomes night later on because that is a game rule of the "daybound" ability and the copy effect prevents the permanent from being daybound.
I cast Metamorphic Alteration to lurker, make it a copy of itself.
What happens when it becomes day?
702.145e Nightbound is found on the back faces of some transforming double-faced cards and represents two static abilities. “Nightbound” means “As it becomes day, if this permanent is back face up, transform it” [...]
702.145f Any time a player controls a permanent that is back face up with nightbound and it’s day, that player transforms that permanent. This happens immediately and isn’t a state-based action.
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Thus the permanent will transform (become front-face up), however, the copy effect will continue to apply in layer 1 and it's visible and copiable characteristics will be unchanged.
It will not try to transform again and again because 702.145f only applies to a back-face up bound-type TDFC. It will also not transform as it becomes night later on because that is a game rule of the "daybound" ability and the copy effect prevents the permanent from being daybound.