This feature of not losing XP is allowing players to go into death, to hide from opponents, then come out at no loss of XP and attack them. Its been a while to fix the XP loss. Is this going to be ever fixed? The time for a warning has long expired.
"Against a level 30 Skadi, a lvl 500 doing a power attack with ending stats of 1050 atack and 750 defense, Died 4 times out of 12 attacks against the boss." 500 levels at 5 points per level = 2,500 skill points 2,500 - 1,050 used for attack = 1,450 skill points left 1,450 - 750 used for defence = 700 skill points left 700 - 500 for Energy (so total refresh every level) = 200 skill points left 200 - 100 (for 50 stamina at every level up) = 100 skill points left 100 skill points to spend on health = 1,100 health (including 100 starting value) (Ok , you do get additional skill points for completing adventures and achievements. About 60 adventures to level 500 at 2 - 3 skill points per adventure is about 150 for those plus around 50 for achievements) So adding an addition 2,000 health revises up to around 3,000 health So can't be great for health
I also have to disagree with losing xp due to boss death. The high level bosses are hard enough to dispose of without having to use 15 stamina hits to kill. Not gaining xp on the 20 stamina hit is enough payment without losing xp as well.