Arelith

I'm really inspired by the 15% physical DI of half stone giant. Can't wait to pick an unbreakable stone giant to play. But thing is, which one is better?
For now, someone is discord mentioned hexblade, which is great. But I'm thinking of something more wild. Like an EDR druid.
DI from race stacks with polymorph DI, together with armor merged. It would be easy to stack DI over 50%.

15 (from race) + 25 (polymorph) + 10 iron armor = 50%
This is not optmal and I still need your help. Which idea could bring more hardness to this build?

Immunity from eq stacks so if you get all of the eq with a high immunity to one or more damage types 5% immunities on all other eq (like rings, amulets etc) you should be able to get more.

Barbarian (plain) 20 / Fighter 4 / Divine Champion 6
Gets -/4 natural from Barbarian
Gets -/9 from feats
10% immunity on rage
15% on stone giant

Equipments:
Honor Guard Halberd (Use One-Hand) Or two if you don't care much about the shield = 5% All
Serpent's Woe Aegis = 5% All
Adamantine Helmet = 10 Bludgeon
Dragonbone / Mail of the Holy Knight = 10% Slash, 5% Pierce/Bludgeon OR if you want for the memes, Berserker Waistcloth = 10% All
Adamantine Bracers = +3/5 DR

Nets you around: 45% Slash, 40% Bludgeon/Pierce
Have a Dwarven Defender Banner you =
Have a Dwarven Defender Safeguard III you = Another -/20 DR, and 65% Slash, 60% Bludgeon/Pierce

OR

Just be a Palemaster with -/9 DR and 60+ AC with crit immunity on top of 30% Slash, 25% Bludgeon/Pierce
But that build has Terrible AB

Hexblade does give you curse of life though, that's 15-18% DI, 5-8% more than your raging barbarian.
But personally, I like barb better.