Understanding the sticking coefficient $\ensuremath{\sigma}$, i.e., probability of an adatom to a surface, is essential for controlling stoichiometry during epitaxial film growth. However, $\ensuremath{\sigma}$ on monolayer graphene-covered surfaces and its impact remote epitaxy are not understood. Here, using molecular-beam growth magnetic shape memory alloy ${\mathrm{Ni}}_{2}\mathrm{MnGa}$, w...