Damaged ECU casing

Yeah, that's the Fuse Box.

It almost looks like you just need a Fusebox cover.  I can’t tell for sure, but it looks like there could be a little heat damage to the case around the regulator “A” grounding plate (upper right hand corner of photo).  

Not knowing how the damage happened or how bad the event was, it’s hard to make a recommendation. The fuse box provides power to all engine functions including ignition coils, injectors, ECU power, and fuel pumps. It also handles the switching control of the two alternators. If it suffered an impact, hidden damage could include broken solder joints, which may not be immediately apparent.  If the case itself is not damaged, and there is no visible component damage, then at a minimum I would replace the cover, cover gasket, and then do extensive ground testing (multiple ground runs). During testing, make sure there are no lane faults, make sure the alternators switch as they should, and test the fuel pumps together and separately.  The good news is that the systems in the fusebox are redundant.  

Yes for sure this is the fuse box.  More detail would help.  The outer cover, the clear part, I believe is available as a spare part.  The housing is not however  given it is plastic you should be able to get it repaired, as long as the parts inside are not damaged.  If the circuit board is broken you will need to buy a new box however.  

Cheers