If C++ and C++/CLI are completely different languages then you must admit that the name of the latter is a misnomer. If you develop a new language that isn't C++ then at least you should have the decency to call it something that doesn't give the impression it is C++.
I suppose and your father have the same surname. Are you the same person? Or do you think you two should have both first and last name differ to be two different persons? Do you understand where I'm going?

C++ is built based on C. Most of the things in C are present in C++ (some of them with changes, like the structs). But C++ and C are not the same language, because C++ has a lot of additions.

C++/CLI is built based on C++. EVerything from C++ is present in C++/CLI. But C++ and C++/CLI are not the same language, because C++/CLI offers extensions for the CLI.

To answer the last question, Microsoft now considers C++/CLI the most powerful language targeting the CLI.