Okay let me give you some hints for the beginning. If I'm saying beginning, when I don't mean the third playthrough!
1. Do not union!!! It's so easy to pick a ''useful'' card (anything else than Revolution) and run to a bridge with Durant alone.
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To give you an example: BF 10-2 (kill Roswell or Rosary) is a typical road-Durant level.
- You can give Durant an item with auto recovery or protection from criticals.
- Pick a card with high movement and run through the golems (horses can move through enemies). Don't attack them.
- Pick your chariot card and move him on the road near the fort. Don't union with other characters. Together with Chariot you have no problems with the witches. Now you can move Yggdra next to a golem to push your cards.
Kill Rosary and get Roswell. Don't get me wrong, they are both weak. Roswell is better, because he can defeat Aegina, X-formation costs less movement and he can wear the boss badana(Always Ace) in order to manage your first meeting with Gulcasa without morale damage.
2. Do not ever use such fucking cards like Revolution :-( . Really helpful cards with high movement are Sanctury, Chariot and Gravity Chaos. After you conquered the bridge you can not lose with Ace Guard or Shield Barrier. Overskill and geo advantage is so much win while union causes only morale damage. ;-)
3. To find all treasures you have to move step by step and explore the map with useless cards when the enemy doesn't want to attack.
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If you increase Durant's TEC with milk(BF with the three burned forts), he will become a god. Now you can play Chariot and Ace Guard much more effective.
4. Gulcasa: Always the same. Find a way to curse him with Gravity Chaos. ;-)