Danny wouldn't have been surprised to see Namor again. He knew how these things worked, having been on the other side of 'I Owe You One' too many times to count (though he did keep track of certain honor-bound debts, but those were pretty exclusive to people he didn't actually like or trust). He could easily assume that one day, Namor would grace the surface world with his presence... or Danny would find himself in such need that he'd need to go knocking on Namor's door. It was inevitable that they would meet again.
However, he was more than a little surprised at The King of The Sea's timing. One minute he was getting all the kids settled down enough to have their lesson and the next the Submariner was in the School of Thunder, doing his best impression of the World's Most Surly, half-naked librarian.
Which didn't sit too well with the group of Middle Schoolers Danny was working with, who were all either staring (for one reason or another), or whispering, or fidgeting or a combination of all of the above.
"Sifu...?" One of the older girls asked, glancing at Danny, though trying to keep a suspicious eye on their visitor.
"Sarah, come up here and lead the class." He said, beckoning her to take over his spot, then started towards Namor, calling back to the children, "Everyone follow Sarah. Sarah, Violet Spinning Lotus Katas, please." Keeping them busy (and faced in the other direction) could at least allow Danny some semblance of privacy to talk to Namor.
He wore a plain white gi, with the School of Thunder logo emblazoned on the back- to match the gis his students wore. The only difference was that Danny's black belt was also decorated with a very small and very subtle golden dragon, embroidered on the right corner. Other than that, and the tiniest hint of a dark mark just beneath his collarbone, mostly hidden by the collar of his gi, there was no evidence that this man also moonlighted as a superhero, and Champion of K'un Lun.
"King..." It was king right? Not prince? Better to assume higher status than lower, really, just in case "...Namor. Thank you for your visit to my school." He said, pressing his palms together and bowing over them. The whole political politeness was second nature now, after such an extended stay in K'un Lun. Danny couldn't say that Atlantean etiquette was at all similar to that of K'un Lun; but with any luck Namor would at least see it as gestures of respect and hospitality, rather than an insult. Because insulting the high strung King (Prince?) of the Seas was really all that Danny needed to make this week a stunningly epic failure.