Reach the box in Demons! mission:
To reach the box in the Demons! campaign mission, create a diversion and then send a cavalry unit ahead along the perimeter of the screen. You can get the box and complete the level much easier.
Reach the box in Dark Day mission:
When deploying your army, take two Scavengers and put them with the general and replace them with two Shaklats beside the remaining two Scavengers. For everything else, put it in a square around the general, with him in the center. At the beginning, use a 4 card on the two Shaklats and Scavengers. On your next turn, send in a Thrall and Scavenger from the general’s square to force your enemy into a passing streak, doing nothing but passing. On the next hour, use a 4 on the Shaklats and Scavengers again. The enemy will then send some units from the right gate to them, but won?t attack. Send the Thrall and Scavenger in further on your turn. The enemy will then start attacking the Shaklats and Scavengers. From here play as you wish, but if done correctly, near the end the enemy will move toward the others when the Shaklats and Scavengers are removed. Have a Scavenger to destroy the left gate and the opponent should get his ninth point. On the next turn, use a card that gives a used unit an order on a Scavenger near the box. You should be able to reach the box. On the final turn, the enemy will attack but not get the last point.