Warhammer: Mark of Chaos - Empire Campaign - Chapter 3, Mission 1

Here are general tips for playing the Empire Campaign in Warhammer: Mark of Chaos on HARD Difficulty. A list of all our Warhammer: Mark of Chaos articles can be found here.
We won't be hand-holding you through absolutely everything, but instead just give tips on situations that we found tricky or that you might not have considered.

Chapter 3: The Enemy Within

Mission 1: In the Name of Sigmar!

Overview

• Easy mission. The half-hour time limit is very long, enough time for you to move back and forth in the map a few times.
• There are items in the northeast corner and in the southeast.
• The optional objective requires you to destroy the two regiments in the southeast. Until you do so, reinforcements will periodically emerge from that location and head for the city.
• Save this objective for last in order to milk it for Experience Points. Clear the rest of the map and park some regiments near the priest (not too close, or you will trigger quest completion), then head back and camp near the southeast to kill skaven reinforcements until the time limit is almost up. Then clear the area and grab the items before rescuing the priest.
• The Warrior Priest starts at whatever level Von Kessel was at when he began the mission, but without any XP toward the next level.
• Since Von Kessel takes point, if you are happy with his basic hit chance, you may want to give him the Warrior Priest's hammer, which does +1 damage.
• Skills:
• You probably brought in the Jade Wizard for the first time in this mission.
• Since we already have a strong front-liner in Von Kessel, skip the Armoured skill and aim for 5/5 ranks in Father of Thorns.
• You could aim for 5/5 in Earthlord, but it is really not that great. Stormlord is also quite weak since your chances of hitting decrease dramatically. Instead, I recommend Spell Focus to maximize the frequency with which you can cast Father of Thorns since it is an awesome blocking skill that paralyzes an enemy, preventing them from moving or casting so you can safely shoot them to death.
• For the Warrior Priest, aim to get both Faith Endures and The Undying Servant at rank 0 (by satisfying the prerequisites). After that, go for 5/5 with The Undying Servant. The Warrior Priest is the only Empire hero who can heal and resurrect, so get these specialities first.