As far as improving your corner of the code goes I would say a consistent style is important but having 500 lines per function is not a style. If someone will complain about efficiency (function call stack etc) then someone needs to identify what parts are truly time-sensitive. It's likely not the entire codebase.

Wrangling a monster code base really requires a product owner. If one person doesn't own the application as a whole then there's no hope of consistency in the first place.