Someone who corrects English language mistakes obsessively, like a grammar
police, making the conversation inconvenient when the original meaning, though expressed imperfectly, is perfectly understandable.
What's different between a Piccadilly Paladin and a grammar
police is that Piccadilly Paladins only correct
English, and are most likely monolingual. They assume the title of "universal language" transcends
English to a new paradigm of being the default language every human should speak, and that a person is unqualified or stupid if they aren't fluent. They've never considered the possibility that a different language can make the world function, and can't comprehend that the ability to talk does not equal choosing to use
English. Severe Piccadilly Paladins think other languages are
nothing more than exotic flourishes meant to entertain the anglophones' minds.
Piccadilly Paladins are mostly Anglocentric, but they could also believe in North-Atlanticism and consider the western world more "civilised" than
humans developing alternatively. They assume that it is rational for every person to want to move to an
English-speaking country, and views imperialism as something irreversible meant to be stopped, but embraced. They act dumbfounded when immigrants want to return to their home country and make themselves useful instead of pursuing a career in the host country.