Killer Instinct

From the games menu, head to multiplayer, human vs human, then exhibition. It will ask you to search for a match or host a private match. Select host a private match and it will place you by yourself in a lobby. From here invite somebody from your friends list to the game and simply win the match.

Every character in the game (besides shadow Jago and Omen) has this same achievement so it would be beneficial to invite a friend and take turns winning matches until you have all 16 character achievements)

All the "friendly" achievements are currently bugged in a good way; you need only finish an exhibition match vs. anyone. Win or Lose, the achievement will unlock at the end of the match, unless your opponent disconnects.

So jump into exhibition matches, pick Aria, finish the match, and then pick "select character" so you can get another friendly achievement. No friends or skills required.