Is the loss of HP in Lone Wolf a one time loss at the time you choose that talent, or is the HP loss active at all times and adjusting your HP every time you would gain HP?
For example, if my HP is 100, and I equip an item that gives me +25 HP, will my HP now be 125, or would it still get adjusted from Glass Cannon?
It's active at all times. If your Vitality is 100 with Glass Cannon and you equip a +25 HP item, you will go to 112 or 113 Vitality (not really sure which, but one of them).
It's
still the most broken thing in the game, but it's not quite that bad.