Up to 5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
3.5-5% Strength for 3.5s on Hit. Stacks 5 times.
5-8% Strength for every 10% of magazine spent during continuous fire. Stacks 5 times.
1-4% Toughness for every 10% of magazine spent during continuous fire. Stacks 5 times.
For damnation: You need 1-2 remaining wounds. Spend all your stamina to get 20% more damage, get behind the Daemonhost, full charge Thrust and hit it on the head (with a backstab as well). Damage stims can help as well to train. I use flamer for toughness regen and some horde control, but weapon can be switched for anything. You have 5 extra points to invest as you prefer as well.