Easy to do:
1. Purchase the +120 toughness morale ability in the Monstrosity tree.
2. Place the ability on one of your morale bars that you aren't using
3. go to monstrosity mode to get the buff
4. change morale bar to a different one with whatever abilities you want
The 120 toughness will stay on the character until something happenes to change another stat or you die, then just repeat.