I associate Namor more with the X-Men, but I think he would be an interesting addition to the MCU if they can distinguish him from Aquaman.
That's an ironic caveat, considering that originally Aquaman and Namor were very different characters, but for the past few decades, Aquaman has pretty much been written as a Namor clone. Namor was always a half-human son of a princess of an undersea kingdom (though it wasn't explicitly named as Atlantis until 1962), but Aquaman wasn't retconned into the half-human son of a princess of Atlantis until 1959 (so who was copying whom?), and didn't become king of Atlantis until 1964. And from the '80s onward, he's usually been portrayed as an Atlantean king dedicated to defending the seas from human rapaciousness and willing to go to war with the surface world to do so, which has been Namor's schtick pretty much all along.