Hold onto your Dragonglass, because we definitely haven't seen the last of Gendry.
According to the Reddit theory posted by user vir804 that's been gaining tons of steam since last night's sh*tshow of an episode, "The Last of the Starks," Gendry will heal his rejection wounds by putting his blacksmith skills to good use.
Specifically, the theory states the last living Baratheon will fashion a suit of armor for Dany's last remaining dragon, Drogon, so that the dragon is completely indestructible. Even with the Scorpion weapon that Euron used to shoot down Rhaegal in episode four, the Greyjoy fleet and Cersei's Golden Company won't be able to penetrate the Baratheon-made suit of armor that Drogon will wear into battle in episode five.
We also may have gotten a glimpse of this theory coming true during the 35-second trailer for episode five. Toward the end of the preview, we see Euron look toward the sky for Drogon (Dany's last remaining dragon), and his expression changes from smugness to shock. But what could be so shocking about seeing Drogon? Euron's already taken down Rhaegal, and he knows what dragons look like already. It must be because Drogon, the last remaining dragon (or is he?!) is now protected by dragon armor.
So if expert blacksmith Gendry (who, BTW, totally has the credentials due to his skills in fashioning weapons for all of the living's forces against the Army of the Dead) finds a way to protect the dragon with armor, then the Scorpion weapon wouldn't work, and Cersei's army and the Greyjoy fleet would be S.O.L. when it comes to trying to destroy the last remaining dragon. *Cue Euron's shocked face.*
Tune in to episode five on Sunday, May 12, at 9 p.m. to find out if the theory comes true.