Leaning towards Indomitable Champion (Heroes of the Fallen Lands), though it is more vanilla than Demigod, but +20 hp raises HS value and makes a tank that much harder to kill.
Unyielding Sentinel (D388) is a possibility too. Double saving throw rolling, and a stance that can negate ongoing damage and give immunity to auras. Better from a 'more options' standpoint, but I don't plan to play Xeno long enough to see much of this.
Same deal with Ceaseless Guardian (D387)...has options, but not much I expect to see.
On an unrelated note, there are few items I can think of Xenophanes wanting or needing atm. On the plus side, Xenophanes is now rich >_>;;
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There is no shame in not knowing; the shame lies in not finding out