I wasn't really sure if this is something that should have gone in the spoilers section, because it doesn't really contain any story spoilers. My apologies if I misunderstood what counts as a spoiler and I put this in the wrong section.

Anyways, as I've started to play I took a look at the achievement list, and they look very interesting/fun. So I started on my way to try to get them all. As a reminder so you don't have to look it up, the 'Tempest' achievement reads: "Kill 6 enemies in under 1 second". Sounds like a fun challenge. Well, I managed to unlock it this morning (I've only played around 2-3 hours total) and man was it glorious.

I don't actually know how to record a gameplay video, but I wish I had. In lieu of a video, I'll just describe how I did it (no specifics, so hopefully spoiler free):

I was in an area which had somewhere from 6-8 patrolling enemies. So I cautiously observed the situation from a nearby pipe. I noticed that there was a small locked room with a swarm of rats in it. I managed to nab the key off a desk when no one was looking and snuck back to the door and set the vermin loose. To avoid getting nibbled on myself, I blinked back onto a nearby roof. The swarm went after a nearby guard, and all other guards in the area came to his aid to hack and slash the rats. It seemed obvious that the swarm was going to die without killing anyone, but I realized that they had grouped up the guards nicely. So I lobbed a grenade into the mix, and boom. 4 or 5 guards died outright, and 2 were left flaming an flailing. Achievement success.

So, has anyone else managed to unlock this achievement? If so, how did you manage to do it?

That's a fun one. I froze time with upgraded Time Bend, walked into a pack of guards, and placed a couple of spring razors at their feet before blinking to an overhanging pipe. Had bits of intestine and slivers of muscle everywhere.

Yeah its not exactly difficult to get after you have have bend time II, although I prefer incendiary bolts to grenades and spring razors. Also, blink II + agility II makes killing tall boys so much easier