It's definitely not impossible to get the flawless triumph, but the difficulty makes it feel like a raid. And this is not what a public event is designed to be like. You need specific loadouts and good team operation to finish the event even with more than 6 people, and that really sucks. I've only completed the seraph tower once after the difficulty change, with 5 other random people. However in that run every one is running a proper build. me an another guy even have anarchy on at the same time. I've tried it on the moon with 7 other people in a 3 man fireteam, but failed because some doesn't have proper builds and don't know what to do. To anyone who are interested in how to possibly get the triumph, or just to complete the tower, you need at least 6 people and separate them into two groups. After two towers come up at the same time, each will take care of one. Supers should be goldie/nova bomb/superman titan, as they can quickly kill bosses. For heavy I would suggest wendigo/anarchy/tractor cannon. If you do this on the moon you can have a graviton lance/sunshot since they are very easy to kill the ads at their spawn point when they are still grouped up. Another suggestion is to have 2 hunters with top tree arcstriker with Liar's Handshake exotic and a one-two punch shotgun, as this can easily 3 shot-melee any boss if you stack combination blow to 3x. However in order to do this the teammates have to throw the balls for them and leave some ads at the spawn point for them to kill.