A number of people have become so famous that their last names have adjectival forms. However, the suffix used to transform proper names into adjectives is irregular in English. A number of suffixes can be used.
The great Armenian chessplayer Tigran Petrosian, a former world champion who was a master of prophylaxis, the art of preventing threats, and who was quick to take advantage of his opponents' mistakes, has given us the word "Petrosianesque" as in "That was a Petrosianesque manoeuvre". Other former world champions of chess whose names have adjectival forms are Anatoly Karpov and Gary Kasparov- the adjectives are "Karpovian" and "Kasparovian". The suffix in Petrosianesque is rather unusual but it does occur in "Kafkaesque", the adjective formed from the name of Franz Kafka. However, the suffix attached to Karpov and Kasparov is rather productive.
This suffix occurs with many other names such as "Chomskian" for Noam Chomsky (note the change of the "y" to an "i"), "Darwinian" for Charles Darwin, "Newtonian" for Sir Isaac Newton, "Orwellian" for George Orwell, "Chaucerian" for Geoffrey Chaucer, "Saussurean" for Ferdinand de Saussure, "Shakespearean" for William Shakespeare, "Mozartian" for Wolfgang Amadeus Mozart, "Bachian" for Johann Sebastian Bach and "Beethovian" for Ludvig van Beethoven.
The suffix -ist in used in the words "Marxist", "Leninist" and "Calvinist", adjectives formed from Karl Marx, Vladimir Lenin and John Calvin. This is a very productive suffix which also occurs in words such as "typist", "artist", "pianist" and "scientist". These words, however, are all nouns rather than adjectives.
In the word "Lutheran" formed from Martin Luther, the suffix is -an rather than the far more common -ian. In "Thatcherite" formed from Margaret Thatcher, the suffix is -ite, a suffix which is relatively rare. It is important to add that these words can also funtion as nouns. It is clear that these words are nouns in the following sentences: "She is a Lutheran"; "He is a Thatcherite".
The suffix -ic occurs in "Socratic", formed from the name of the famous Greek philosopher Socrates. It also occurs in "Napoleonic" for Napoleon de Bonaparte. An example of the use of "Napoleonic" is the phrase "Napoleonic code".
In English, a number of suffixes can be used to form words from proper names. The most common one by far, though, clearly appears to be the suffix -ian.