I completed the grind that shows how much I hate myself. Was it worth it? Probably not. I also did it all solo...because I am insane.
Here's some tips for those still going for it!
Invader: 1k and Sleeper...until you get to the part where you use Truth. Then you dance on the bank with a bubble. Or if you're confident you can slaughter the entire enemy team, just stand on the bank. They will come to you. Also, no one likes you. Not even your own team.
Sentry: You stay by the bank. Don't help your team. Your only help is either standing at the bank or running after the Invader. Johtunn works great here. Melts blockers and Invaders. Also...run Truth instead of Johtunn if you can. Make Invaders regret being born. If there are no Invaders or blockers present, stay at the bank and listen to a podcast while you wait for something to happen. I recommend the NoSleep Podcast.
Collector: The worse your team is doing, the easier it is. Ignore blockers if you can, because having your bank drained helps you send out more blockers to make the Half-Banked medals easier. Leave the game after the Primeval is up. Trust me when I say, your team won't miss a Collector. Also if you did YOUR JOB, your team will already be winning by a longshot and won't mind losing someone. If you're a Titan, I heavily recommend using Skullfort and Shoulder Charge for collecting. It keeps your health up and allows for you to kill enemies quickly.
Reaper: Riskrunner and arc grenades work wonders, as the Reaper armor set allows for pretty much infinite grenades. It's mainly about completing a lot of games to get the High Value Targets. Massacre medals are broken and have a random chance of popping up when you follow the requirements. I will just straight-up confirm that they are broken. People here will argue and say that since they got one recently, it isn't broken, but they won't accept the fact that these medals are indeed broken as hell. I even took time to experiment to make sure. How do you get these broken medals then? If you have good internet, you won't need to worry. It seems they pop up properly if you aren't going through lag hell. If you have bad internet like me, SLOW DOWN. It seems like a bad idea for a speed-based medal, but it does help against the lag. I got them all in 2-3 days. I could have got them in 1, but...even I don't hate myself that much. Also...don't be a fool and do Reaper first. Do it last. I did it third, and I still hated it. It's the hard one, so just do it last.
Ready to be downvoted into oblivion for pointing out something in the game is broken!