Putting extra points into Deathlord does not increase the defense on the Character Screen.
In my case stays at 679,822 regardless of hard points invested.
On respec, with far less attributes invested, defense at Deathlord level 1 is at 679,590.
Just a little less defense than the setup that had sMax Deathlord and ~3k more str.
Something is fishy with how the skill actually calculates bonus defense compared with what the skill description says.