TimeShift

Boosting partner needed / preferred.

Simply play 100 multiplayer games of Timeshift, can be ranked or player and can be any game time, also you do not have to win the match for it to count towards this achievement.

Fastest way, host 1v1, or deathmatch player matches, with kills set to 1, one shot kill, on MP1.

This is easier and faster when done on player matches. Find a boosting partner, and host a custom preset game on death-match. Select the Map Rooftop Excess, and also select your custom preset ( needs to be created). Set the game to two players, and the score limit to 1. The person hosting the match should win the first ten matches. This will unlock "Have it your way" Achievement. Now you can switch so the other player can unlock the achievement or just keep playing.
After a match is done, you can restart the server and play again without every leaving the game like "Ranked matches". Win or lose, you will unlock "Time Shift Veteran" Achievement. If you trade off the Wins, then both of you will eventually unlock " Time Shift Champion" Achievement.