So in Fate/Zero Berserker is by far and wide my favorite character, mainly because he reminds me of Artorias from Dark Souls. Both are insane knights with tragic backstories.
Thankfully, unlike what the picture shows, you can still use guns. Berserker has the ability to turn literally anything into a weapon. He can kill you with a milk carton. I'm serious. To quote Rider "Whatever he grabs onto with his hands becomes his Noble Phantasm." I'm a little rushed when making this so I'll have to be quick.
Remember this is meant to mimic a character, not be effective in relation to the game. I'll try to add as much as possible when I can. Sorry for the rushed info, but I wanted to get it down before I forgot.
We will be using Excalibur (how appropriate, eh?) as the base frame for this build, with the Default skin. The helmet to be used is Pendragon. If you're on the Xbox One the Jade and Emerald skins are perfect. The coloring is full black (with a few dark grays) with Red energy (so original I know but what can you do?) and the weapons will mimic the same appearance. Remember thanks to Berserker's ability any weapon (even firearms!) goes.
Excalibur will be modded entirely for physical durabilty and ignoring and extra abilities. This does make sense concerning Berserker, as his mad enhancement increases physical prowess at the cost of all but the most basic abilities. Increasing health, shields, and armor will be perfect. The Rage (also very appropriate) and Quick Thinking (not so appropriate) will be good for durbaility as well.
As previously stated Berserker is capable of wielding any weapon (yes even a carton of Greedy Milk) be it a blade, a hammer, or a firearm. So use your favorites weapons, it doesn't matter the mod setup! Go crazy! (Get it?)
This will be lacking a syandana unless you have Steel Meridian's or the one belonging to Arbiter's of Hexis (sorry cape lovers) and will be making good use of sigils and armor. Black will be used for accessories (with the rare dark gray) and for that glow on his chest we will be making clever use of the mastery sigil. Coloring your sigil black with red energy, and properly lining it up (will post details when I can) you will be able to mimic (to a degree) his aura on his chest.
For legs you will be using Harkonar, for shoulders Prisma Daedalus, and for the chest Eos Prime (for more red glow)
I did not have alot of time to work on this (about 20 minutes) so I will try to edit it afterward whenever given the chance. Very sorry.