DOOM

Patch 6.66 Update: Now the Harvester demon unlocks at level 21

Go into multiplayer. Before a match starts you have to select your loadout and a demon loadout (in most multiplayer modes anyway). Select The Harvester.

There are two ways to become a demon in a match.

1. During the match, a demon rune will appear. Run into it and you will transform into the Harvester.

2. If an enemy gets the demon rune first, killing them will drop another demon rune. Grab it quick!

Once you are the Harvester, kill as many enemies as you can. The 10 kills are cumulative. You might get this in 1 match, or you might need to be a demon a few times. Personally, I got my 10 kills after two attempts.

It is possible to boost this along with every other MP achievement on Doom.

requirements: minimum of 4 players

once you are in the multiplayer menu, push and select Asia-Pacific. As of writing this the Asia-Pacific servers are D-E-A-D as a doornail. nobody is playing on any mode.

once everyone is ready, select FIND A MATCH and select either Team Play or Team Deathmatch. Team Play has a few modes that spawn no demon runes (I believe freeze tag and infernal run do not, message me if I am wrong or missing modes). Team Deathmatch always has demon runes appear.

I suggest using Team Play to boost demon kills for the simple reason the modes it offers will give you cues on where to meet up. Domination and Exodus have icons on your HUD everyone can meet up at.

The game should match 4 boosters within 30 seconds everyone is searching.

demon runes take 1:30-2:00 to spawn and only last for about a minute. to get the most out of each rune, have the team that gets killed meet up by the rune before it is collected then move onto your meet up spot (again, its easier to do this on Team Play modes)

if you're well organized, you can get up to 8 demon kills with 1 rune

As of the 6.66 patch on 7/20/17, all DLC for the game is free. Along with the patch, multiplayer progression has changed.

The Harvester demon does not unlock until you reach level 21.

Make sure you select Harvester when the match starts.