I just completed the MR 17 test and I found it to be the worst one thus far. Its random spawns of melee globes make practicing not as beneficial as other tests you can practice for. But practice does give a sense of the map and how to best attack it, so definitely practice. The placement of some of the globes leaves much to be desired as well -- practice will give a sense of where they can spawn.
That being said, here's what worked for me:
1) Ignis (wraith) -- not having to worry about aiming so much and reloading helped a great deal. Spray and pray worked great. Mod for infested.
2) (And this is the kicker) Nezha -- His number one allows him to not only get a speed buff, but to also leave a persistent trail of death for the infested who are chasing you around in a confined space. Mod for energy (there are no globes and you cannot use energizing dash), duration, and strength. By the time I bothered to look the counter said that there were only 10 infested left and I had hardly fired a shot.
3) Arcane Consequence -- Headshots with the Ignis trigger this pretty consistently so you get a parkour buff that helps tremendously as well.
4) Get to the top platforms as much as possible. Getting down for a globe is much easier than getting up to one. If one is low, go down, hit it, and then head back up. I found that spotting globes was much easier from this vantage as well.
I failed in practice a lot, but once I put this setup together it wasn't too too bad. You'll find most of the mobs get eaten by Nezha's fire and those that are left quickly get melted with the Ignis.
Hope this helps!
