This is another one of those episodes that doesn't seem to be going anywhere, but manages to sneak in a major plot development in the final moments. In this case, it was a bit predictable. Who didn't realize that Clark's blood was going to transfer power to Zod? I have no idea if that was something established in the DC canon as a possibility, but it just seemed like the obvious consequence.
In fact, it could be said that this was a largely transitional episode designed to remind the audience of all the plot threads that are currently up in the air. The situation with the Kandorians is particularly complicated. Some of the Kandorians are eager to follow Clark's lead, while others are devoted to Zod. Some of the Kandorians are acting without Zod's permission, experimenting on humans, but somehow this is not to be taken as a lack of confidence in Zod's leadership. There are enough factions and subsets within the Kandorian camp to allow the writers to do pretty much anything without contradicting themselves.
Unfortunately, it's a tangle that the writers are going to have to unravel if they want the season to succeed. There are already plenty of fans complaining about the Kandorians, so making them obtuse and fractious is one hell of a risk. It's already clear that Zod is manipulating Clark with half-truths and lies, so why not simply leave it to that?
Zod's characterization is another issue. I still think it would have been more interesting to portray Zod in a more positive light, even if he was maintaining a certain degree of Kryptonian brutality. After all, the writers keep reminding the audience that Zod and Jor-El were friends and allies, even with the apparent betrayals that came towards the end. If the message is that Zod has a good and noble side, why do we only see the duplicitous part? It fits audience expectation, but it's also predictable as a result.
The same complaint can be lodged against the current portrayal of Tess Mercer. In the eighth season, I thought the writers did a capable job of taking her from her Lex-clone origins to something a bit more substantial. Despite her actions and choices, she seemed to have a genuine desire to help Clark. The issue was less her design and more her method. Now, it's hard to fathom what her goals are.
One bright spot was the revelation of Chloe's secret plan to defend against powered Kandorians. While the visions of the future may no longer apply, the end of this episode strongly suggests that at least some of the Kandorians will be regaining their powers and making trouble for Clark. Chloe and Oliver now have the weapons to help in that fight. (Of course, as the future vision aptly demonstrated, this could be just as easily used against Clark.)
As far as the rest of the episode is concerned, it was nice to see Lois show off her fighting skills again. Her romance with Clark is coming along very well, even if it sometimes strays into overly sweet territory. The central villain wasn't particularly interesting, and his methods seemed a bit more gruesome than has been the standard for "Smallville". It felt like the writers were going for edgy, but settled on "shocking".