  The recent advent of artificial structures has triggered the emergence of
fascinating phenomena that could not exist in natural compounds. A prime
example is twisted multilayers, i.e., moir\'e superlattices represented by
magic-angle twisted bilayer graphene (MATBG). As in the case of MATBG,
unconventional band hybridization can induce a new type of superconductivity:
artificial band engineering by twist induces properties different from the
original systems. Here, we apply this perspective to a monolayer superconductor
NbSe$_2$ stacked with a twist on doped graphene. We show that the
superconducting states of the NbSe$_2$ layer change dramatically by varying the
twist angle. Our result shows that twist tuning, in addition to substrate
effects, will provide a strategy for designing monolayer superconductors with
high controllability.
