If I copy Nicol Bolas, the Ravager with Scion of the Ur-Dragon whilst Scion is my commander, what happens? Do I get my Nicol Bolas Plainswalker? Or does it not happen because I must send Scion to the command zone in order to keep him from exile? I am confused because Scion's name changes to Nicol Bolas, it is not like Lazav, the Multifarious where it specifies his name staying the same.
Edit: I neglected to mention that I am attempting to pay and transform Bolas.
In this scenario, if Nicol Bolas's activated ability Scion of the Ur-Dragon acquired from Nicol Bolas resolves, Scion of the Ur-Dragon will be exiled (or go to the command zone, your choice [C.R. 903.9]), but won't return to the battlefield, since Scion of the Ur-Dragon isn't a transforming double-faced card and the effect says to return that card to the battlefield transformed (C.R. 711.10a); where that ability says "Nicol Bolas, the Ravager", it means only Scion of the Ur-Dragon, regardless of what that permanent is called at the moment (C.R. 201.4b). (Note that if Scion of the Ur-Dragon is your commander, that object will necessarily be a card other than a double-faced card [C.R. 903.3, 108.1].)
EDIT (Jul. 2, 2020): Edited to conform to rule update with Core Set 2021.
EDIT (Dec. 17, 2020): Edited to conform to rule updates in the meantime.
Edit: I neglected to mention that I am attempting to pay and transform Bolas.
(or go to the command zone, your choice [C.R. 903.9]), but won't return to the battlefield, since Scion of the Ur-Dragon isn't a transforming double-faced card and the effect says to return that card to the battlefield transformed (C.R. 711.10a); where that ability says "Nicol Bolas, the Ravager", it means only Scion of the Ur-Dragon, regardless of what that permanent is called at the moment (C.R. 201.4b). (Note that if Scion of the Ur-Dragon is your commander, that object will necessarily be a card other than a double-faced card [C.R. 903.3, 108.1].)EDIT (Jul. 2, 2020): Edited to conform to rule update with Core Set 2021.
EDIT (Dec. 17, 2020): Edited to conform to rule updates in the meantime.