The first Tier of Uatu the Watcher requires you to watch 5 replays.
The first thing you need to do is play a multiplayer match. You can do this in a local match with a second controller, or in an online match. When the match is over, select “save replay.” Next, choose multiplayer from the main menu and then select replays and watch the replay you just saved. You can watch the same replay 5 times. You can also hold to fast forward though the whole replay and finish watching the replay much faster.