No that guy died. Anyone who blows the horn dies. With the possible exception of Danaerys as she has enough "blood of the dragon/old valyria/whatev" to be mostly* immune to fire.
The black priest with Victarion was sent by the High Priest in Volantes, he was sent to council Dany, and he's using Victarrion to get to her (I'm guessing he will either trick Vic or convince him not to use the horn, but to give it to her as a present to win her over). The High Priest is the one who has said that Danaerys is AA and the entire LoL congregration (basically all of the slaves and common people in Volantes, including most of their soldiers) believes it. The Nobility in Volantes is terrified of the priest because Dany represents freeing slaves and 8 out of every 10 people in Volantes is a slave. They wanted to hire the Golden Company (most respectable Sellsword army, with 10k men) to kill the priest before it got out of hand, but it's too late now, and besides the Golden Company was waiting outside of Volantes for "Aegon" and Dany anyway, to combine their forces and retake the Iron throne.
What i'm most curious about regarding the show is Gendry+Arya. If they stick with the books, Arya's story is the most likely one to get cut down big time. She'll be off in Braavos alone, becoming a Faceless man. They'll show a snippet here and there of her training to remind the audience that she still exists and is progressing but her story has nothing to do with KL/Wall/Dany which is basically the 3 main focal points of the show.
In the books Davos sends Edric storm across the narrow sea to one of the free cities so that Mel can't sacrifice him after the purple wedding. This is a major plot point in the Davos/stannis story and convinces Stannis that he needs to save the realm to win the kingdom rather than win the kingdom to save the realm, so he goes to the wall to save the NW from the wildling army, so that really can't be cut/altered in the show. So Gendry will be "rescued" somehow out of reach Mel, and at the same time Arya will be standing on some docks not too far from Dragonstone waiting to board a ship to Braavos. I'm thinking the Show may have them both go to Braavos, perhaps on the same ship, so that they can stick together and give more screen time for Arya (and Gendry too, as neither him nor Edric storm really matter any more in the books after this point. Gendry has one scene where he meets Brienne but any of the BwoB can fill in here).
purist's might complain that the change would impact her decision to leave (her entire family "dead" and all of her friends abandoned her being the reason she left Westeros) but I don't really see it. Her family being butchered and her desire for revenge on those who have wronged her is what motivates her to leave, having one of her friends back in her life wouldn't change that. As since Gendry has to leave anyway to avoid being ritually sacrificed it's not like she could convince him to stay in Westeros anyway. She wants to leave, he has to leave, they can leave together nbd.