When you at level 24-32 in Atlantica, this will be your first encounter with some tough enemies. If you know how to fight them, they're easy. The flying Evil Monks can only be hit by projectiles or skills.

They also have a powerful poison skill. A Monk's Holy Guard can cure it but a lot of players will not have one yet. The second set of enemies here are just as powerful. These are the ogres. The White Ogre are weak against skills but strong against physical attacks. If you have Swordsman, 2 level 20 Flame Swords will kill a White Ogre. The only good spot to train here are at the Moss and Sorcerer Golems. The Sorcerer Golems will cast a weak heal on any hurt enemy making them waste their turn. The Moss Golems are the only ones who will seriously attack and they are weak. They can come in large groups if you're not careful, but if you can hit multiple targets with axes or guns, they will barely attack you.

The Naga Queen will be the first boss with other mobs in the room. If you did the Bandit side quest, you have Reinforcement Scrolls you can use against the boss to call the other mobs in the room to your side. Otherwise the mobs have a fairly high damage and can attack the first and second row simultaneously.