Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: Are flash units for Nikon compatible with the X-E2, either auto or manual? If not, are adapters available?
Document: You're really need to stock up on memory cards (and get a big hard drive as well), the RAW files are huge coming in at 33.4MB because there are no compression options available. My 36MP Nikon D800E's RAW files in comparison are usually between 35-40 MB using the lossless compressed option.Flash:  Don't expect to be using the built in flash for much. It is anemic.
I never would have guessed that kind of shot would be possible, but the performance of the newer X-E2 is similarly strong.Handling: Solid and well-built. Plenty of manual buttons and dials that allow you to make speedy, intuitive changes to settings (a dramatic contrast with the NEX series, which takes good enough photos on auto mode but are a total pain when you are forced to burrow into software menus to change most shot settings). A solid weighty body with no flexing or creaking.
Same with my Nikon D800. With any mirrorless, it is hit and miss. With Fuji X, it is mostly miss.Anything else other than my son, Fuji XE2 does easily. For my son,  DSLR with top of the line AF system is still the only game in town.2) Negative 2. Flash system is a weak spot of Fuji system. And for some reason Fuji keeps coming up with new cameras several times a year but do not address the issues.
It may look cool there but I have to arch my hand to get at it.Manual:  The manual is pretty much like most camera manuals, a lot of "Put switch A in position B to enable function C (not available with modes D,E,or F). ", with little explanation of anything. There is no index, so make sure to download a PDF so you can use the `Find' command.
The Fujifilm X-E2 is just the third compact system camera I've spent time shooting with and have really enjoyed it. I previously used a Sony NEX-5N andNEX-5T, but rarely shot with either of them. I mainly rely on my Canon DSLR or my smartphone for most of my needs, which are relatively modest.
Exposure bracketing however is somewhat disappointing with only 3 frames with  1 EV being available. For a camera that seems to target serious photobugs, this is an odd oversight.The X-E2 is clearly meant for photographers whose main intent for the camera is shooting photos, not just because of the control setup, but also the video capability which seems like a bit of an after-thought. There's no dedicated video button and options for video pretty limited compared to the E-P5 or most other cameras.
The focusing and the controls are just not appropriate for quick responses by me to fluid situations. On the other end, I now use a D800E for fine art and architectural images and a D700 for events (not weddings). The X-E2 will not replace either of those cameras for a lot of reasons.I had tried previously to use a point and shoot as a walk around camera, a Leica D-LUX-4.
DNG raw images from the M8's unfiltered 10MP sensor can appear sharper than those from the X-E2. These issues made me want to very accurately focus the X-E2, and hold it very steady for the sharpest images.8. CR2 raw images from Canon's 20MP EOS 5D mk II appear sharper than those from either the X-E2 or the M8 in Lightroom 5.4.
I've had a few mirror-less and micro 4/3's cameras, but I always felt like they were missing something - either not functional enough to replace a full DSLR or still too large to replace an easy to reach camera phone. This new Fujifilm X-E2 takes a pretty big leap forward in closing the gap on these two extremes.The X-E2 is a fully capable camera right out of the box.
Hopefully firmware updates might improve this, and video quality is certainly very good with the 60 fps and HD capability. Full manual control is also available during video which is always a great plus as is focus peaking. The external mic port however is not a standard 3.5mm but 2.5 mm so won't work with most DSLR external mics. I'm guessing a 3.5mm to 2.5mm adapter will do the trick but haven't been able to test this yet.
Answer: Yes, I've read that sb600/900/910 function manually on the camera and using some wireless triggers, even cheap cowboy studio ones.    I use a yongnuo st-e3-rt on my x-t1 and to fire a canon 600 EXRT flash and previously used it on the x-e2 so system is versatile though you might want to go to your camera shop with your flash to try it out first if you have other models of flash.