Finished Looks
The Gamer Storm Assassin from Deepcool has a unique color scheme all its own. Paired with an NVIDIA GPU and one of Gigabyte's Sniper series of motherboards, the green and silver colors would make for a splendid match, of that there is no doubt.
Clearance around the motherboard's heatsinks is fine.
Again, it is easy to see that the Assassin won't have any issues clearing the heatsinks on most motherboards, though it is a close call with the top expansion slot.
Like most heavyweight CPU coolers, the Gamer Storm Assassin blocks most DIMM slots. Using memory modules like Corsair's Dominators won't be possible with this cooler. However, this issue is common to nearly all of today's high-end air coolers.
The biggest problem is the potential to block the top expansion slot. Depending on the motherboard's expansion slot arrangement, or the height of the expansion card, the heatsink or fan clips may cause a short. Keep the top expansion slot on your motherboard in mind. Again, this is an increasingly common issue among the largest air coolers.