Deathstroke is at the mercy of the Society, a clandestine group of the most dangerous rogues on the planet. Deadline has brought a case against Slade due to Deathstroke's stealing of his contract, gun, and hand. Vandal Savage leads the prosecution against Slade, and the Riddler is his defense attorney. The Society wants to know if this act was fair play, and the only way they can do this is to test if Slade Wilson is still evil.
That premise might seem a bit goofy, as one would think that a more three-dimensional rogue would not perceive themselves as evil with few exceptions. Many who do perceive themselves as such only take on the title ironically.
Well, this book kind of has your back there, as, in the latter portion, Ultra-Humanite, Hector Hammond, the Reverse-Flash, Killer Frost, and Black Manta all speak up on the subject, explaining why they are not evil. As a result, Savage and Riddler seem to be the only ones really taking on this whole "Secret Society of Supervillains" thing wholeheartedly.
Also, if you are wondering why Killer Frost is here given that she is now a part of the Justice League of America, this book has you covered there too. If you're wondering how the Reverse-Flash isn't dead after recent events in the Flash comic, don't expect an explanation there. I imagine if any of the creators were questioned on the subject, time travel would almost certainly work into it. Continuity complexity is kind of written into the character of Eobard Thawne.
At the end of the day, it's more of a test as to which side Deathstroke is on now, and that is as complicated as one would imagine. I'm still not sure what Slade's endgame with Defiance really is, and I still kind of dig that.
(Spoiler) This book does do a bit of an ass-pull, as a portion of it is a hallucination brought upon by Hector Hammond. However, you could probably guess that some of what you're seeing isn't real when Deathstroke starts cleaning out DC's rogue's gallery. It kind of works though, because I like seeing how Slade would kill the likes of Hector Hammond, Reverse-Flash, Black Manta, and Ultra-Humanite. It's a gory affair, and it's fun.
Deadline does come off looking like a whiny loser by the end too, and that's pretty entertaining.
Carlo Pagulayan's art is seamless and effective. It's detailed, kinetic, and all-around gorgeous. He does some damn fine work on this issue, and every panel is in the A-grade. Jeromy Cox's color work backs up Pagulayan well, and each page pops with great color art.
Deathstroke #25 is an interesting insight into Slade and the nature of evil in a group whose full name is the Secret Society of Supervillains. It teases out some character depth, and it also teases the idea of a self-identifying supervillain. This one gets a strong recommendation. You should definitely give it a read.
It even gives you extra story at no up-charge, and that alone deserves a reward.