To be totally honest, I really, really, really wanted to like this episode. If it went well, it could really set up characters like Black Adam, Captain Marvel, and all those other mythical characters. Sadly, however, it was pretty upsetting.
Although, maybe I'm being a bit pessimistic. It's mainly that, compared to Homecoming, this kinda seems like a letdown.
I liked the building on Oliver and Tess, especially how Oliver's adapting to the public life, although uncannily like Tony Stark. Ironically, the opening suggested for Oliver for the presentation at the beginning of the episode sounds familiar to the Iron Man 2 opening, plus the dancing girls. Also, I love how Oliver and Tess still have a tense relationship, but Oliver is willing, albeit reluctantly at first, to take a step back and trust her, even a little bit. By the time the episode ends, she's regained their trust, and they fully invite her into the League.
Clark revealed his secret, finally, but Lois already know. Symbolically, it's huge, and it shows he really trusts her.
However, though Erica Durance is a knockout, not only in general, but as Lois. However, her performance as a Lois being possessed is slightly dismal. Some parts are good, but generally it's meh.
However, what I love the bit between Isis and Clark, where she taunts him for him not trusting her completely, right before she binds him to the table.
However, the special effects for the episode, however, are pretty dismal. Either using clear wires or too much CGI. I like Smallville a lot, but I'm not blind to it's faults.
Ultimately, the best parts of the episode was the Oliver-Tess relationship, which I hope to see more of. It created a great dynamic between them. That, and basically all of Oliver's lines. Justin Hartley is a fantastic actor, and I hope he gets to continue the role after Smallville ends. He's like Jensen Ackles, like one of those actors who just look great, are great at making scripted comebacks seem snappy and natural, and has a great voice overall. Welling seems to have a more serious tone to Clark now, since Homecoming, a bit tougher, a bit stronger, a bit braver, standing up just a little bit straighter, which is very nice. But I LOVED when Clark 'revealed' his secret to Lois, although basically jumping him is kind of an unusual reaction, even if you did know. But still, its a whole new step in their relationship.
I also liked the little 'Mini-Lex' subplot. It seems that Alexander's growth is sped up so much that, by the end of the season, he'll be Rosenbaum-sized. Hopefully, this is a way of them trying to write him back onto the show.
Overall, I give this episode a 7/10. Pretty good, but don't get your hopes up for it too much. It's a meh episode, but then again, so are most 'Possession' episodes.