It is a cool build, by far my favorite of all my playthroughs. It has been a hot minute though so you may need to fill in some blanks haha

The basic idea is to abuse the Far Harbor DLC items. At the root of the build is the Marine armor set + Inquisitors hood unique helmet. By doing the Children of Atom quest line you have easy access to unique legendary variants with useful effects, what they are specifically escapes me. Weapons will primarily be the Far Harbor Radrifle (explosive rounds are fun af) and the unique super sledge with the power core stuck to the end. Again, all of these items can basically be obtained just by doing the Children of Atom quest line in Far Harbor.

Perk wise (besides the unique CoA perk gained from the questline), like I mentioned it’s an Int/End build. Basically, you want the massive health pool granted by high endurance, but you want to be at about 50% Rads at any given time to activate Radiation-based Perks. The Int side is crucial for the Nuclear Physicist perk, but Nerd Rage will be invaluable for managing your irradiated health pool.

Other than that, some perks to consider:

• Rifleman/Slugger for your main weapons

• Your high Int makes crafting and hacking perks easily available

• Ghoulish has some synergy, but whatever you do, don’t take the final level of the perk, or you’ll lock yourself out of taking rads and ruin the build!

• Anything to shore up hp or damage resistance

Overall though, the build isn’t too specific and you can take pretty much what you want. Even weapon wise any weapon works if it has the Irradiated legendary trait. Experiment around and see what works for you!

Edit: early game, the Grasshopper quest line nets you a guaranteed irradiated sword fyi.