There are different levels of authoritarianism:
Lv.1: fined for a few months income.
Lv.2: 1 year suspended sentence.
Lv.3: 5 actual years in prison.
Lv.4: 20 years in Gulag, if you're very strong have chance to survive.
Lv.5: get executed.
Lv.6: all your family, including family dog, also gets executed.
Lv.7: half of your national minority gets deported/evicted to Kazakhstan/Siberia death camps, the other half gets genocided.
Stalinism is pure Lv.7, Tsarism and Italian Fascism are between Lv.3 and Lv.5. German Nazism is between Lv.3 (for Germans) and and Lv.7 (for Jews).
Putinism is between Lv.3 and Lv.5 (they practice out of court assassinations, like Nemtsov). I.e. Putin can be compared with Mussolini, but still needs bit more to caught up with Hitler, although what Putin did to Syria comes very close to genocide (the Syrian nation may not survive that).