I believe Gecko Moria will return. As an ally and member of the Straw Hat Grand Fleet.

With the latest devil fruit reveals in the last chapter of one piece I was pretty surprised that one of them wasn’t Moria’s. Since last we saw him he was about to die to Blackbeard on Hachinosu, trying and failing to avenge Absolum.

If you didn’t know Moria is a tragic character. He braved the Grand Line and it broke him. His entire crew massacred by Kaido. His massive ship now a decrepit old ruin.

My headcanon for Moria is this. He was a strong runt similar to the Worst Generation, but when he faced his Grand Line trial, similar to Luffy, Kidd, and Bege, he didn’t lose an arm, get saved by a Shichibukai, or bow down to a Yonko, he got annihilated by Kaido. I believe after this he lost all faith in himself and in return sought out a devil fruit that only works by stealing the power of others.

I believe after Kaido killed his entire crew, he sat in that decrepit old mansion in sorrow, until three people came, who heard about Moria in his heyday and wanted to lift his spirits. People that believed in him, respected him and wanted to share his dream. But after being crushed again by Luffy, I believe they all went their separate ways again. Leaving Moria alone again.

And after getting crushed again during marineford he had lost all of the remaining will he had and returned to his former shame. Until he heard that Blackbeard had captured Absalom, someone who believed in him, his crewmate. At rock bottom, seemingly unable to sink any lower he west out to rescue his former friend. But was defeated again.

Moria is a tragic tale of the Grand Line. They copy his backstory and use it for a villain in one of the darkest One Piece movies ever made Baron Omatsuri, where it just shows you how far you can fall to this sea.

More evidence for this I think would be Brook. Similar to Moria he lost his crew to the terrible goings on of the Grand Line, but when Moria only looked to his regret at what he did and resenting Kaido, Brook chose to remember the good times they had together and move on.

Even at Marineford, Moria warns Luffy that at his current level he is too weak for the Grand Line and he will lose everything. At the time we thought this was just banter. Moria hated Luffy for ruining his dream of Oars right? No. This was a warning, from a man who had lost everything already, and was on the brink of having nothing left.

And I think the fact that none of Blackbeard’s main crew has his devil fruit means he could still be out there. And if he wants revenge against Blackbeard there’s one surefire way to get it. When he hears that Luffy has beaten Kaido. After what he thought was unthinkable at Marineford, he just might be willing to believe in himself again.

Theory by kingbam161 (https://www.reddit.com/user/kingbam161)