Hello, my spartan company is on the cusp of getting the Achilles helmet. The one commendation holding us back is the assassination. Any tips? Fastest? Best game mode?
Play swat
Or Snipers.
the most quiet gamemodes have been mentioned above but if you want to see your enemies but dont want them to see you, then you must move slowly to a place what is likely to hold opponents and that way you can usually surprise them or at the start where you know the enemies will rush, then you can wait for a while for them to walk past you and slowly follow them and after assassination you just change to another likely position (like waiting around corners unseen for a few seconds).
Also, you can rack up a handful of assassinations playing Shotty Snipers if you get Pegasus II. Since lots of people like to spawn camp Blue corner from Yellow house across the way, you can usually sneak up on them from behind and rack up some assassinations throughout the game.