After pulling out the Mana Sword, monsters appear in the area. You and Elliott end up in a hole with the Mantis Ant.

Kill Mantis Ant

Even if you die in this battle, a mysterious man will revive you, so don't bother eating any candies during the battle.

Your only attack is to swing your sword. Don't forget to wait for your sword to charge up to 100% before you swing it again. If you leveled up the sword, you can hold the sword button until the gauge says 1/1, then release the sword button to use a stronger attack. However, it may be difficult to do this while dodging attacks.

The Mantis Ant can encase you in toxic bubbles using the Acid Breath attack. Just wait for the acid bubbles to go away.

The Mantis Ant will slash at you if you are standing in front of it, so be sure not to stand in front of it.

The Mantis Ant can also shoot some spinning energy at you. I don't think that there is a way to avoid this.

Mantis Ant can also put its claws in front of itself to block your attacks. Be sure not to hit it until it stops blocking itself.

Try to stand to the left or right of Mantis Ant, wait for it to raise its claw, then run away, then after it swings its claw run back and hit it with your sword. If you're lucky, you won't get hit.

Eventually you will kill Mantis Ant and it will explode. You will be healed up and receive a Sword's Orb. Then the man who talked to you earlier will pull you up. But now you have to face the consequences of pulling the Mana Sword.