As realmwright enters the battlefield, choose a basic land type.
Lands you control are the chosen type in addition to their other types.
Nope, static abilities of permanents do not have effect unless they are permanents (not cards in graveyards, libraries, hands, or exile).
For instance, see {Elderscale Wurm}. It has a static ability like {Realmwright}, but if the wurm left the battlefield, yiu could die now. Same with the realm dude; if he is not on the field, you so not reap the benefits.
RESOLVED
Thank you.
Np