*****Update 126.96.36.199: The Moon Lord Leech will now counter any healing from weapons. This video features the vampire knives for extra healing which means it isn't very relevant in terms of tactic, but might be fun to watch either way. Will update whenever I can.*****
The Moon Lord is the final boss of Terraria (1.3) and is the most challenging fight in the game. There are ways to make it easier, like not going melee, but I think it works quite well. First kill took me 16 minutes, now it's down to 11 minutes on the second kill.