Tainted Grail: Conquest

Pathfinders are part of the Children of Morrigan faction, so fight in melee combat and rely on raw damage and Armour reduction for offense. Defensively, most cards will grant points of Block, which will completely negate the damage of one hit per Block point, regardless of how large or small it is, though there are some cards that also buff your Armour for the hits that you cannot Block. Pathfinders gain a buff called Focus each turn where they take no damage, which grants a 50% increase to damage to all attacks and stacks with itself indefinitely, but will be lost when even 1 point of HP damage is taken. Damage taken to a Barrier will not disrupt Focus, which can be used to your advantage if you are unable to Block all incoming damage. The Pathfinder Ability card is to double the effect of the next Stance (Blue) card played, which will be mainly used for gaining points of Block to avoid damage. The Ultimate Ability is charged by playing Stance cards, one Charge per card. For every 3 Charges, you will draw a card when used and for every 6 Charges, you will gain a point of Energy, meaning the maximum 12 Charges will draw 4 cards and give 2 Energy points.

Combat as a Pathfinder is relatively straightforward. You want to use as much Energy as is necessary for Blocking or otherwise removing incoming damage, as preserving the Focus buff is the most important thing you can do. Against large numbers of enemies, or enemes that attack with many small, low damage attacks, generating Barrier is a better choice than Block, as you cannot gain a large number of Block points often. Once you are sure that you will not lose your Focus buff, spend any Energy you have left on attacking or debuffing the enemy while you wait for Focus to build. You should try and avoid using your Ultimate before 6 Charges, as the extra Energy is the more useful part of it and while you are Blocking all the incoming attacks to generate Charges, you are building Focus, so when the time comes, you can deal one turn of extreme damage.

When choosing new cards, try and balance offensive and defensive picks, though bias the deck defensively if you find you are taking damage during combat. Cards that generate more than one Block, Block over mutliple turns and Barrier are cards you will use often. High cost offensive cards may seem like they have no use, but with the right Passive Skills, you can have enough Block/Barrier to be able to unleash full turns of damage, or one very, very powerful Skullcracker.

When it comes to Passive Skills, there are some absolute must haves:
Persistent Defense (Gain 10 Barrier per unsused Block)
Overprotection (draw an extra card per unused Block),
Natural Block (if you end the turn with 3+ cards in hand, gain an extra Block)
Safety Measures (gain 10 Barrier per turn).

Nice, but not essential skills:
Focused Mind (each Focus is now a 75% buff, not 50)
Delayed Punishment (after playing 4+ cards in a turn, the first hit of next turn has a 400% damage buff)
Sharp Focus (start with one Focus already every combat)
Slayer (draw 3 extra cards on turn 1)

If you follow this formula and fight every battle you see, you should reach level 20 in the third area, just before you fight the 3rd guardian.