STAT

Here is the rundown of all attributes and combat properties,

LIF (Life): Affects HP.

STR (Strength): Raises PWR (Power: physical damage, mostly melee) and DefPhy (Physical Defense).

DEX (Dexterity): Raises ACC (Accuracy: physical damage, mostly ranged) and DefPhy.

INT (Intelligence): Raises MAG (Magic: spell damage) and DefMag (Magical Defense)

FAI (Faith). Raises SPR (Spirit: healing properties) and DefMag.

If you are going to level up, strengthen the stats that you really need. You just can't go all-around jack-of-all-trades. Already decide what you want for your hero from the start to the finish. What they seem like in the beginning can be changed in the long run. I am very partial with the Priest, as you can remember, because it takes too much time and investment for him to contribute damage wise. There is no real assurance that you can go far with a Priest when the drops (offensive magic spells) will not just go your way.

Remember, a Rogue can be a great frontliner given its skillset. You can put her on the frontline cast the immunity skill and backstab the middle lane and weaken the casters / range enemies because they tend to be too soft when it comes to physical attacks. Swap again with a beefier or healthier hero to soak all the damage the next battle until the skill cooldown recharges.

This is just an example. You can be diverse, and think of what you can do with the heroes you have chosen. You might be able to pull off an all caster line-up (which can be actually possible because there is a Battlemage) and cast spells until you clear the dungeon. Or not.