"Arrow" fans were left baffled when Oliver Queen accepted Ra's Al Ghul's offer to be the head of the Leagues of Assassins by taking Ra's place. Shocked fans watched his transformation from vigilante to villain as he commenced his training with Ra's. Has Oliver, now Al Sah-Him, truly gone to the dark side?

It seems he has and will continue to do so in this week's episode. As per the official synopsis by SpoilersGuide, Oliver has finished his training and must complete two final tasks before becoming the next Ra's Al Ghul. It seems that one of his tasks might be to capture team Arrow. In the promotional clip, Oliver Queen is seen capturing the team and locking them up at the League of Assassins' headquarters. The other crucial tasks, the one that will shock fans world-over, is that he must marry Ra's daughter, Nyssa.

As per the promotional clip and episode's description, Ra's will give his daughter two choices: marry Oliver or die. It looks like the upcoming episode will see Oliver tying the knot with Nyssa. Showrunner Marc Guggenheim had previously teased to TVLine that a wedding takes place on the May 6 episode and it seems to be the marriage between Oliver and Nyssa.

The description of "This Is Your Sword" also states that Malcolm makes a surprising offer to team Arrow. Most likely, Malcolm Merlin will offer his help to the team and battle alongside them in order to take down Oliver Queen.

Roy Harper will be seen one last time in episode 22, as Felicity tells Thea he is alive. Thea goes to see Roy and two most probably hookup one last time. Another TVLine report states that Felicity and Ray aka Atom will call it quits for good and have an emotional exchange. Guggenheim said, "They do have a very meaningful exchange in Episode 22, but we're not going to do an on again/off again thing with them."

TVGuide reports that the season three finale ends in a cliffhanger but not one in which fans are wondering about a character's death. Moreover, the big bad of season four will also be revealed.

"Arrow" airs its upcoming episode on Wednesday, May 6 and its season finale on May 13 at 8 p.m. ET on CW.