To get this you need to get the MVP ribbon award in 100 multiplayer games. The games need to be played through the multiplayer button on the main menu but can be private matches vs. the ai. To get mvp you need to:
1. Win a game killing the most enemy units on your team
2. Kill at least 1 enemy unit
3. Be on a team of at least 2 players.
The fastest way to get this I've found is to go to the map editor and create a custom scenario. For Player 1 place 2-3 castles and for Player 2 place a single spearman in the middle of Player 1's castles. You don't need to do anything for Player 3. Save the scenario as whatever you want then start up a multiplayer game, set game type to Scenario, and select the one you just saved. Make sure there are three players (yourself and two ai), set Player 3 to your team, and start the game. Your castles should kill the spearman and you win instantly.
You can change your civ and the opponent civ to whatever you want to go for the "Win as/defeat civ X times" achievements. These will also count towards
The Anytime, Anywhere achievement in Age of Empires II (2013) worth 59 pointsYou have fought on every type of map, against every type of opponent in history. There may be those who will still stand against you, but they do so with respect. Huzzah!
The Five Hundred Victories achievement in Age of Empires II (2013) worth 63 pointsIt has probably been a long time since you stopped counting your battles and victories but your fans (and foes) will remember. This battle marks your five hundredth multi-player victory!