  Trilayer graphene exhibits valley-protected gapless states when the stacking
order changes from ABC to CBA and a gate voltage is applied to outer layers.
Some of these states survive strong distortions of the trilayer. For example,
they persist when the outer layers are partially devoid yielding a system of
two trilayers of different stacking order connected by a strip of a single
graphene layer. Here we investigate how these states respond to another
perturbation, i.e., the presence of magnetic defects, which we model as
pi-vacancies. We show that the gap states hybridize with the defect states and
strongly spin-split. More importantly, it is demonstrated that by changing the
gate voltage value one can change the spin density of the gap states and the
corresponding currents at the Fermi level.
