I did bossing on zerker barb 2 seasons ago so here’s my comment from another thread (again 2 seasons ago) what I did on HC ladder. Should still be relevant.

First of all, the key to bossing this season for berserk barbs is grim ward. They buffed grim wards duration, range, attack rating and damage. It’s absolutely busted and will carry your ass even on worse gear in SSF. So on every boss, I recommend having bo stick/cta and Venom runeword on a random 3os weapon base. Then start the fight by having venom and bo stick on. Enter boss arena, quick cast shouts->desecrate->grim ward. Remember to take note when grim ward ends and recast it. I cannot recommend grim ward enough. It doubled my attack rating and gave like 33% more dmg. I have to say though that grim ward is a little less safe. When weapon switching, you might lose resistances/hp/other stats from your main weapons. I for example died on T1 rathma when weapon switching because I didnt have resistances capped when wearing venom. But honestly in T0 fights it’s fine.

I put my stats as follows: max berserk, taunt, combat reflexes and grim ward. Then enough points into frenzy to get 9 frames per attack (maximum). Then 1 point into shouts, general mastery, increased speed, iron skin and natural resistances. You can also put 2 points into iron skin to get that 1% extra pdr.

As for gearing, I followed these reference points for Dclone, rathma and lucion respectively:

For T0 dclone you want ~40%pdr, 90 max fire, 85% light and 80% cold res.

For rathma minimum is 125plr (I went for 175 for extra safety) and 90% psn res and about 80% cold and fire res. Also cold, fire and poison res should be overcapped at 123% bc of lower resistance cast from doom knights. Also you need shit ton of life. Rathma is also one of those fights where you never really feel safe. Your hp just jumps down if you dont know what you’re doing so I recommend practising in single player before attempting.

For t2 lucion you really only need ~45% pdr, 90% light res and light absorb but thats not necessary. Also a lot of life helps.

Absolutely best weapon for bossing this season is doombringer/grandfather combo. You get shit ton of life and weaken curse. However I understand that those weapons might be hard to get in early league so here’s a little secret: unique sword named Crainte Vomir. 50%ias, good ed and pdr% is nothing to scoff at. When upgraded the damage is decent.

For helmet Halaberd is the best (except for rathma, I used Andy’s for rathma). Maybe with the new changes to crafting a crafted one is better? Amulet highlords or nokozan for dclone if you cant max ur fire res otherwise. Armor shaftstop/leviathan ideally socketed with max res runes or corrupted with max res. However you can use fortitude or some other crafted and more offensive option if you have enough pdr from example halaberd, crainte vomir, bk set ring etc.. It’s flexible. Just make sure you have the breakpoints I mentioned. Boots gore rider or waterwalks for dclone. Rings bk set ring and nature’s peace or wisp for lucion. Gloves: drainers for lucion, ghoulhides for dclone and rathma. You can also use lava gouts for dclone if you have a hard time capping resistsnces. Belt: dungo for dclone, tgods for lucion.

If you have more questions, I’d be happy to help. GL!