Priest Class

Priest - The Holy Warrior
Priests wield gigantic weapons in the form of Crosses, Totem Poles, Axes, Scythes, or Rosary Beads. Their giant weapons make them fairly slow on movement and attack, but they strike punishing blows. Priests are the only starting class with a direct heal, albeit a fairly weak one. Priests also have a buff called Strike, using Strike will make the first few levels very easy for a priest. Leveling smasher is also a good idea prior to level 18, it's very strong.

At level 18 a Priest can upgrade into:

Exorcist - Giant Weapon masters, strong physical and magical attacker. Exorcists are unique in that they can focus on Magic attacks, physical attacks, or be a Hybrid of the 2. Magic Exos use Rosaries, physical Exos use Scythes, Totems, or Axes

Monk - Fast and agile, monks can dodge to and fro with Dash and Sway. They plant their Giant Weapons in the ground to free their hands, and strike much faster because of that. Monks usually use Totem Poles.

Crusader - They are capable of being a pure Support class in DFO. They get heals, buffs, debuffs, wear plate armor, and can turn a weak party member into a powerhouse. Crusaders also get some light-based magic attacks. Crusaders are well liked in parties and usually use Giant Crosses or Rosaries.

The priest class is one of my favorites in DFO, I'm surprised how strong they are when the name Priest usually denotes weakness and heals in RPGs. Priests are also probably the easiest class to get from level 1-18 with, in my opinion.