This is build concept I've been tossing around for a while and went through and tested a few times to try and get the feats and such worked out. Any way here it is any comments/ help or suggestions would be great, thanks.
Skills: Max Tumble/Pick Pocket/Lore/Discipline on your HS Lvls Max Lore & Dicipline on Barb & WM lvls Intimidate:25 for Terrifying Rage Persuade: 8 Search: 4
Feats: (Barb lvls 1-13) 1. Dodge/Expertise 3. Mobility 6.Weapon Focus: Large Weapon( I used Great Axe) 9. Spring Attack 12. Whirlwind (WM Lvls starting at lvl 14-20) 15. Toughness 18. Armor Prof. Heavy (Barb Lvls 21-35) 21. Alertness 24. Iron Will 27. Terrifying Rage 30. Improved Crit: Weapon 31. Epic Weapon Focus (Barb bonus feat) 33. Great STR I 35. Thundering Rage (Barb bonus feat) (HS lvls 36-40) 36. Epic Prowless/Epic Will 39. Great STR II 40. Great DEX 1
Pros: -Shapstrong at lvl 42 -7 attacks per round with HS secret and haste -50% immunes to all but sonic with HS secret -10% or more base physical immunes
first, shapestrong rage definitely requires 30 levels of barbarian pre-LL. I once brought a character to the secret who had only 28 levels like your build + some LL levels, and she wouldn't get the secret. Very frustrating experience.
Second, your build leans very heavily to the offensive side. Way too much, I think. I may have overlooked something, but I think the following will hold true for your tank:
You really need defenses on a build, especially on a STR build like yours, which is supposed to be a tank. You didn't even take the Armor Skin feat. The only way to survival is not to get hit in the first place, and the ways to achieve that are high AC and/or concealment. Barbarians get neither. I don't know how much UR equipment you have but I really believe a clean STR tank needs an UR subrace or better and must be clad in UR equipment.
About saves, 50 reflex is required for Dachy; 50 reflex, 50 fort is minimum for desert; all saves 60 is good for hell. Max saves you will get without LL save feats is 22 base + 26 from plusses and maxed stats at level 40 (if you have the equipment, that is), which will leave the toon standing stoned/lying imploded and sanded in desert most of the time, where normal STR tanks usually only stand stoned (reflex saves). You will not get a chance to display your uber offensive capabilities, much less tank for anybody.
Oh, and my usual recommendation: just try it out! Seriously, build the toon, take it to desert and read the combat log. There is really no better way to learn
If you use a large race as it stands you wouldn't need to worry about shapestrong, so for example if you went minotaur, you would at this point effectively lose nothing by skipping that ability. That's if you really need to wield a large weapon. You could just as easily remain prismatic and go with scimitar or something I imagine.
Other things that came to mind include cutting the Armor Proficiency feat as you can get it on an item you can just buy in town and take it off after you equip the armor.
I would recommend taking the legendary save feats if your saves are that bad, you might be able to fit them in as you didn't specify what you were taking in the LLs. If necessary I would move some HS levels in real early so you had time to qualify for the WM feats, assuming you wanted Legendary Luck and such.
This could be made to be functional, a build would have to be fully laid out and calculated to really determine if it should be on the chopping block I guess. You might end up with a "why not other options" situation but it could be something to think about if one were so inclined.