Slade Wilson
Oliver got his suit on and raced down to the bridge where he knew that he was going to have to kill Slade, to get Felicity back. He told Diggles and Roy they could have the night off. He had to go alone to even stand a chance at getting Felicity back.
When Oliver arrived on the scene, where Slade had supposedly had taken Felicity, he began to look around. He was completely alone. Then he started to hear big footsteps. He turns around to see Slade holding Felicity with a sword to her throat.
"Slade, what do you want, I came alone," he shouted to make sure that Slade could hear him.
"You are the one I want, we have some unfinished business to take care of," he spoke with a little bit of a growl.
"Okay, let her go then it will be between you and me," Oliver replied. Slade gladly let go of Felicity.
"Felicity, RUN, Diggles will meet you at the mansion. I have to finish business with Slade," he yelled and Felicity did exactly that.
All of a sudden, there was thud. Felicity turn around to see what it was. It was Slade hitting the ground. From what Felicity could see, Oliver killed Slade with a single arrow to the heart.