The longer Bashers remain alive, the stronger they will be. Bashers are one of the toughtest fighter classes. They are common and have a low mana summoning requirement. Keep bashers alive as long as possible, and use them against weaker enemies. Each time they attack, they will gain strength.
Captain skills
Your Captain has skills that turn the tide in battle. However, rival Captains can also use their skills. Captain skills usually have long cooldown times.
Enhancement tiles
Guard enhancement tiles from enemies and use them to your benefit. Some levels have tiles that enhance your life, attack, or other attributes when they are passed over. Use such tiles whenever possible.
Healers
Have two or three healers in your line-up. This will ensure that you will get one, even though available soldiers are selected randomly.
Secondary attack effects
Some fighters have skills that result in secondary attacks or statuses.
Soldiers
Once your fighters queue is filled, you may need to swap soldiers. Replace weak soldiers with stronger ones as you progress. Stronger troops require additional mana to be summoned. Have some weaker troops ready to use as easily-summoned fodder. Warriors can change lanes above and below to unoccupied spaces. It is not necessary to spend mana to summon new soldiers if you can just reposition to get the same tactical effect. Magic users can attack soldiers that are adjacent to each other, either horizontally or vertically.
Vanguard
The vanguard is the only soldier guaranteed to be in the queue at the start of each battle. Choose it carefully.