I think the problem with Modi, like extreme politicians (e.g. Le Pen in France or the Tea Party) in other democracies is that some of his utterances are contradictory to Enlightenment humanist ideals. It remains to be seen if the subset of his views that can be considered to be extreme are just rhetoric or if he intends to act on them. Historically, such politicians resemble the nationalistic polities of pre-1945 Europe and post-colonial South America.

The bright side about India is that its sheer diversity and the existence of regional leaders (who do not belong to Modi's party) serve as checks and balances. As an example, regional parties organized on linguistic and non-traditional ideologies (communists, anarchists, etc.) basis have captured close to 140 seats in the parliament, including clean-sweeps in several States such as Tamil Nadu (population ~70 million), Odisha (population ~40 million), Seemandhra/Telangana (population ~85 million), and West Bengal (population ~90 million).