General thing: Unchained Barbarian's temp HP fit the theme better (in my opinion) than cBarb's con bonus, and unBarb has a stance rage power that boost AC. Something to consider for any of ther below options.
Have you considered the Beastkin Berserker archetype? It lets you turn transform as Beast Shape while raging, and starting at 8th level you could actually turn into a lion. That does somewhat wreck havoc with your AC (get Mage Armor!), but you get the bonuses from Rage in addition to the bonuses form Beast Shape. It replaces three rage powers, but comes with build-in pounce, so you don't need Greater Beast Totem.
As an alternative, you could ask the GM to let you use the Mooncursed archetype with a lion rather than tiger, which is a 100% downgrade and thus balance wise completely kosher. It lets you turn into a medium lion at 1st level, a large lion at 11th level, and even a hybrid form (like a lycanthrope) at 5th level. It doesn't get the normal Rage bonuses, but keeps all the Rage Powers, and like Beastkin Berserker gets pounce without totem powers, so you could maybe find something good and/or thematic.
The animal form also has somewhat weak AC (although at least no AC penalty from Rage), but the hybrid form is actually an AC bonus.
Either form could get an additional natural attack with Chaos Reigns, makign a body slam, which would fit the mythology.
If neither is to your liking, you could, of course, play a regular natural attack-centric Barbarian. It wastes some potential, though, as additional natural attacks (e.g. gore from Spirit Oni Master or Helm of the Mammoth Lord) are hard to fit with that theme. There is a feat for Rend, aptly named Rending Claws, but it's pretty weak.
Rage Powers would of be the usual - Beast Totem line, Superstition, maybe even the thematically nicely fitting Come and Get Me (/Taunting Stance), which as usual pairs well with the Dazing Assault feat.
The Stalwart and Improved Stalwart feats make a lot of sense both thematically and mechanicall, you probably want Reckless Abandon for them.
