No bug, the HP adjustments is the 20% Unyielding Sentinel + 25% Epic Defensive Fighting +10% Winter hp adjustment. Oh, and full reaper tree including con bonuses x that adjustment is the difference between reaper and normal. 900 ish reaper hp x 1.55 = 1400 ish.
Here is AC breakdown, this is for For a Few Flowers More, original has more dex and less shield AC and is about the same. Feat bonus is from past lives, Misc bonus is from destiny and enhancement trees, mostly US, and other sources. I don't know the exact breakdown.
PRR breakdown is:
50 Epic Destiny (15 LSM + 15 C3 LD + 5 C2 GMoF + 5 Divine Bulwark + 10-30 Deific Resilience (Deific Warding Feat)
36 Past Life Divine + PDK
99 Gear: 33 Enhancement + 30 Artifact + 21 Light Armor BaB 21 + 9 Quality + 6 Mythic
5 Greater Shield Mastery
21 Sentience ish
18 Enhancements and misc I have no clue where ish
Updated For a Few Flowers More and put a link in OP! Also updated OP for newer players to not take the +threat, and instead reduce threat.