A question about the new depowered "Truth" Superman

[Danileriver23]

So I was captivated by the new take on superman. I generally find superman stories boring because I feel like there are no real threats to a guy who can pretty much do anything, but the idea of taking all that power away and seeing how he reacts seemed cool.

I was only reading Greg Pak's run with Aaaron Kuder on Action Comics and it was great! Really fun and different take on the icon. But what I really wanted to know was how he lost his powers "permanently". Now, I know johns introduced the solar flare that removes his powers for a day, but something happened to make the change seemingly permanent and even the fortress of solitude can't recognize him as kryptonian anymore.

Like I said, I was only reading the action comics run, and I know "truth" is playing out across all four of his titles, but have they revealed anywhere what caused his powers to leave for good?

[Jody Garland]

Yeah, that was in the Superman title. It was the work of a villain called Hordr, IIRC, and some fancy technology.

[Sacred Knight]

Its alluded to that it started the second-to-last time that Superman used his solar flare while fighting Hordr. When he flared, a mysterious sillouette snuck up behind him and touched him, causing Superman pain during the flare but he disappeared once the flare was done and with no other apparent ill effects at the time. From that point forward he began having issues replenishing his energies, until he got to the state he's at currently.

I'm thinking at this point in time that this person will be revealed to have been Vandal Savage, but as of now the identity of the silhouette remains a mystery.