So what advantages to comprehension or usability would you like to offer over Elixir? (as it doesn't really focus on type/category theory like most other FP languages)
Pretty common in FP languages to have implicit returns. A function HAS to return something. Ideally, a function is just a mapping between one value and another value. Wouldn't make much sense to have explicit returns.
For everything else there are guards, or just a simple if/else block. If everything is an expression (And if you are making an FP lang, almost everything should be.), the last expression will always be returned.