Here is the full list of all 31 Tactics V: Obsidian Brigade achievements.
Durehn takes charge of the Obsidian Brigade.
Acquire the Flame Mace.
Fend off the Sea Beast.
Kill the Ice Golem.
Survive the Observatory Assault.
Kill the Duke of Loren.
Kill the Bearman Chieftain.
Kill the Thanati Leader.
Destroy the last Demon Portal.
Have a soldier reach level 10.
Have a soldier reach level 20.
Have a soldier reach level 30.
Have a soldier learn all Skills and Powers of the Warrior Class.
Have a soldier learn all Skills and Powers of the Fighter Class.
Have a soldier learn all Skills and Powers of the Rogue Class.
Have a soldier learn all Skills and Powers of the Archer Class.
Have a soldier learn all Skills and Powers of the Defender Class.
Have a soldier learn all Skills and Powers of the Healer Class.
Have a soldier learn all Skills and Powers of the Basic Wizard Class.
Have a soldier learn all Skills and Powers of the Temperature Wizard Class.
Have a soldier learn all Skills and Powers of the Physical Wizard Class.
Have a soldier learn all Skills and Powers of the Energy Wizard Class.
Have a soldier learn all Skills and Powers of the Necromancer Class.
Have a soldier learn all Skills and Powers of the Blade Wizard Class.
Have a soldier learn all Skills and Powers of every Class.
Win a battle without taking any damage.
Hit 3 opponents in one attack.
Hit 5 opponents in one attack.
Hit 7 opponents in one attack.
Kill a Drake
Have a soldier learn all Skills and Powers of the Druid Class.