Campaign 2. Mission 4
Agrael must survive.
Follow the only available path and go right at the T-junction.
Capture the city of Hallin (1). You can't build an inn in there, so visit an inn near the city (2). Hire an elfish hero and help him develop. Give him the army from Hallin and send him to recruit Hunters from all 4 recruitment points around the area (R).
Have Agrael visit the dungeon (3) and capture Ur-Nebyrazias, which will eliminate the orange player. Pay a visit to the dragons (4) guarding the passage there.
Bring 100 Hunters or Master Hunters to the Dragons.
The Dragons will let you pass if you bring Hunters to them. Bring more of them along with you (120-130) as their numbers decrease daily. Reach the passage (5) and go to the city of Erewel. A strong unit is defending it. You can use your supply hero to weaken them, and then move in with Agrael's demonic army to finish the job.
Campaign 2. Mission 5
Agrael must survive.
There's no hurry here. Take time to scout around the map, you'll need it to navigate through the islands. There are no cities in this scenario. The only recruitment points are around (R). There are also two spots where you can upgrade your units (U).
Sail to the right. Land on the island and visit a Tower and a lookout point (1). Continue on to the North-East, land on the beach, visit another lookout point, and enter the dungeon. Go left at the junction there and use yet another observation point (2). Go back to the underground and go along the previously unused path. Make use of the recruitment points here. The passage is to the South on the next island. Follow the underground passages to reach the island to the North. Go left, to the teleport. Go down and follow the yellow road. Build a ship on the next island. Now's a good moment to go back to get additional units. It's good to wait near the recruitment points (even a few weeks if you have the patience), and then pay a visit to the upgrade point.
Land on the island near the center (3) and visit the lookout point there. Sail to the sandy island in the middle. Enter the dungeon once again and use the short corridor to reach the exit. Once on the other island, go to the South-East. Defeat the dragons guarding the bridge (4). Tieru awaits you a few steps ahead.