In Black Panther: Wakanda Forever there was one critical moment that wound up going to waste. Namor, the antagonist of the film, shouted "Imperius Rex!" in response to Shuri's battle cry of "Wakanda Forever!" but MCU movie fans are unlikely to be familiar with Namor's catchphrase. The moment flew over many people's heads, and it was a fleeting statement to occur in such a high-stakes battle.
Namor is likely to appear in the MCU again, which makes it surprising that Imperius Rex wasn't better introduced. Marvel has a history of using certain phrases over and over to build excitement and create a continuous thread between movies. But the opportunity to capitalize on Namor's use of the phrase was lost in Black Panther 2 as he only said it once, and it got lost since it was used as a response to "Wakanda Forever!" with absolutely no explanation or real indication about what it could mean.
Why Namor's Catchphrase Is "Imperius Rex"
Imperius Rex loosely means Empire King and is a fitting battle cry for Namor. He is one of the oldest characters in the Marvel Comics with his first appearance dating back to 1939. He has fought many foes and "Imperius Rex" is well known among comic book fans. However, Namor says "Imperius Rex" only once in Wakanda Forever, making it more of a verbal East egg. Similar to the battle cry of "Wakanda Forever," Namor uses the phrase to intimidate his enemies and build himself up. There has never been a direct reason in the comics as to why this is his catchphrase, but regardless it has become iconic.
Why Did Black Panther: Wakanda Forever Waste "Imperius Rex"?
One of the most iconic lines in the MCU, "Avengers Assemble," took years to pay off with audiences thrilled to see Captain America completing the iconic line in Avengers: Endgame. To an extent, "Wakanda Forever!" has already become equally popular, especially since Chadwick Boseman's death. Since "Imperius Rex!" is used so frequently in the comics, the MCU missed the mark in claiming another popular phrase in Wakanda Forever. It is possible that since the line isn't in English, it would be harder to integrate into the storyline.
Since it can only really be used in battle, it makes sense that Namor only said it a single time. Because Black Panther: Wakanda Forever was already action-packed, Marvel may have simply not wanted to set up one more thing for audiences to keep track of. With Namor likely to appear again in the MCU in Phase 5, audiences almost certainly haven't heard the last of "Imperius Rex!" as his catchphrase may take a little more time to become iconic within the cinematic universe.
