Diablo III: Reaper of Souls

Belial is the final boss of Act 2 and will spawn in several phases. The first phase requires you to deal with a lot of snake guards. Shortly after that he will spawn as a miniboss that you have to get to around 20% life before he decides to become gigantic and start bashing you with heavy punches. It is pretty easy to avoid his attacks because of the huge green pools he spawns. Simply remember that standing in green stuff is bad and this should be a breeze. Once he is defeated the trophy will pop.