Transition metal chalcogenide is a key host for van der Waals magnets, many of which maintain magnetism down to the thin layer limit. Recent discovery of ultrasensitive magnetism in Fe-based transition metal chalcogenide magnets - Ni-doped Fe5GeTe2 and Fe-intercalated NbS2 - raised the question of how such tunable magnetism is achieved, and how do they differ (if at all) from elemental...