Warhammer: Mark of Chaos - Chaos Campaign - Chapter 2, Mission 5

Here are general tips for playing the Chaos Champaign in Warhammer: Mark of Chaos on HARD Difficulty. At the end of Chapter 1, Mission 6, we chose Nurgle instead of Khorne. 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 2: The Wrath of the Rat-Kin

Mission 5: Battle of Briartangle

Overview

• Another easy mission. Your objective is to leave the Elf Mage alone until you have cleared the map. This is also your chance to level one of your cannons up to level 3.
• After this mission, you switch back to Thorgar.
• You can still access stores, so now is your last chance to buy anything from the Skaven stores for this Chapter.
• The next map location for Thorgar will be Brigand's Glen. This will change his store. He will no longer be able to buy any artifacts from the old store, and the Chaos Champion will no longer be available.
• If Thorgar chose Nurgle at the end of Chapter 1, one Sorcerer of Nurgle will be available at Brigand's Glen, but you may not want to buy him yet. We will discuss this in Mission 7. If you chose Khorne, no additional hero is available in Brigand's Glen.

Walkthrough

• Deploy all your forces in the southwest corner.
• Leave most of your force near your cannon and take a small, mobile force with you -- maybe just the Grey Seer, Kasqit, and one regiment. You don't want traffic jams.
• When you sight an enemy, stop. Target them with your cannon (to get your cannon some experience) until they get close, then engage.
• If your regiment gets slightly blown up by your own cannon, your Grey Seer should be able to fully recover your models with the Favoured Minion spell.
• When your cannon has reached level 3, move them somewhere safe and focus on getting experience for your other regiments and your heroes.
• Move up to the centre and northwest to destroy all enemy units that might wander down to the southwest. The free Assassin hero here starts at the level your main Skaven hero (Kasqit) entered the map, but without any XP accumulated toward the next level.
• Then head southwest to clear the elves.
• There is an Elven ballista here. You could rush it, but you will probably get tangled up with fighting the elven archers.
• Instead, plant your Grey Seer and regiment between it and your own cannon. Have your cannon blast it while your Grey Seer uses Favoured Minion to recover lost models from the elven cannon blasting its regiment.
• Once clear, move to the southeast corner to attack the elves there.
• Destroy all tents to find loot.
• Near the Elf Mage there are tents to the west of him, and tents to the south.
• To avoid the Elf Mage for now, use your cannon to destroy the tents at an extreme distance away.
• Somewhere in tents to the south is a potion once you have destroyed the tent. Taking that potion will typically get the Elf Mage's attention and he will pursue and attack, so don't grab it until you are ready (or just pick it up automatically when the mission ends).