Jace's Galactic Guitar-lord

Space Sculptor
When Jace's Galactic Guitar-lord enters the
battlefield, choose a sector (alpha, beta, or
gamma). Whenever another nontoken creature is
assigned or reassigned to the chosen sector, it
phases out. Whenever a creature you control
phases in, it explores.
{4}{u}: You may assign or reassign target creature
to any one sector (alpha, beta, or gamma).
That's galaxy livin'.