In team fights you want to focus their AP or AD carry. You should decide which one to focus based on how fed they are and how easy they can escape from you. If your team is ahead and have good follow up you can simply initiate with your ultimate and then E, pulling the enemy team in closer, and then popping your Zhonya's active when they turn to focus you. Otherwise, you want to wait for your tanks to engage and then try to land your Q on the enemy AP or AD carry. It's extremely important to land your Q in team team fights as it's your only form of gap close and without it you'll just be kited to your death.
The Howling Abyss is used for "ARAM" (All Random All Mid) matches, and is five vs. five.  The difference between the Abyss and the other maps is that there is only a single narrow lane of Turrets and an Inhibitor, and no neutral jungle area. Thus, rather than skirmishes and hidden movement, the Abyss focuses exclusively on large team-fights in the sole middle lane. Players cannot return to their allied base to replenish health and mana or purchase items unless they have been killed.  ARAM was launched as an official mode in September 2013. 
I saw this link on that other site and didn’t even bother clicking because I knew it would be some nonsense. But this is far beyond what I imagined. “fight” and hotel stay. “I’m good company somethings.” The third-person usage. The lack of capitalized words at the start of a sentence. Look, it’s a holiday and I don’t plan on dragging anyone, as to save my strength for Fleet Week debauchery. I’m okay with the Brandon persona. But Jeff is too much. This is too much. I’m surprised there’s not a disclaimer at the bottoming stating “Jeff is not a prostitute.”