I need help getting my last remaining online trophy from Doom 2016

[SFK-1]

Hi! I found this website after the Doom subreddit failed to give my post any attention, since it's already so packed with daily posts, apparently. It's kind of an urgent thread I need to do, so if you guys don't mind, I'm just gonna copy and paste my original post:

 

After days of using the XP Bounty rune and miserably grinding my way up to Echelon VIII so I could unlock challenges that reward a piece of Cyberdemonic Armor, - which is what I need to unlock the final online trophy, "Beauty Is Pain" - I finally reached Echelon VIII today. 

 

A few challenges for CD armor are now available, while the rest are locked behind Echelon IX, but I really don't want to have to spend more 2 straight days dying and sucking in the online mode, no matter how fun it is. So I'll have to do with the four challenges that I unlocked right now that will reward me a piece of cyberdemonic armor. Linked in this post are the images of each challenge and the completion requirements. I have no idea what I have to do to get those medals and commendations, and what my strategy should be. Please help me, guys

In case you can't visualize the pictures:

 

•  Kill the top enemy three times in a match (0/5)

 

•  Critical Chain medals (0/15)

 

•  Massacre medals (0/1)

 

•  Hard to Kill commendations (0/5)

EDIT: It appears my image somehow didn't upload. Oh well, here's a third party link: https://ibb.co/D57JFK3

[ItzNooh]

By this point you have most definitely gotten the achievement but for a massacre medal you need 15 kills in one life which can easily be boosted