@Riot, once the lore team gets to Zed...

...Please don't forget that he's not entirely a villain.

All he wanted was recognition from his master. If he led Zed back to the light and balance, then Zed would have never become so vindictive. Instead, he was ousted. He was kicked out of the school pretty much just because he wanted to impress his master.

It's not Zed's fault that the ninjas forbid all shadow magic. He could have been convinced to use it for good (I guess you can say he is using it for good, since he is trying to turn all Ninjas to the shadow path, which makes them indisputably more powerful than before.)

And why didn't Zed kill Shen when he staged the attack on the temple? Surely Shen was nearby when Zed came out of the temple with the master's head. He just told his minions to attack and watched his shadow apprentices put their powers on display. Shen was so busy saving his friends that Zed could have had MANY chances to kill Shen and he didn't. Because he doesn't want to kill Shen. All he wanted to do was to beat Shen, and by that point, he already did.

And on top of all that, according to the wiki, it was hinted that Zed had a relationship with Akali. So from all of this, we know these things:

1. He has a heart

2. He knows the weight of his actions "What I have done cannot be undone"

3. He doesn't want all Ninjas in the world to be weak just because someone had forbidden shadow magic. He wants everyone to be strong with him. "Secrets kept are weapons wasted" "Brave the shadows, find the truth" "No technique is forbidden"

Zed is not strictly a bad guy. That's one of the reasons why I love him so much, because he's mostly an anti-hero rather than a complete villain. He has an emotional reason for everything that he's done, be it opening that Pandora's box, to staging the assault on the temple. He thought it was too late for the master to forgive him, and depending on your point of view, he could be right.

So remember all this once you get to Zed, lore team: He's not exactly a good person, but he's not a pure villain either. Everything he's done is driven by his emotions; his desire to strengthen people like him, and his drive to impress the people he cared about (his master and Shen and Akali)

If you want some context on how I would believe Zed would act, here's a highly upvoted piece of my own fanfiction featuring a fight between him and Shen: http://boards.na.leagueoflegends.com/en/c/fancreations/g6wTk6bc-zed-vs-shen