Dire Foes are enemies that spawn after battle. Once defeating the last enemy, instead of launching the post battle scenes and stats music dies and everything goes quiet. Then a Dire Foe will spawn with two invincible minions. Dire Foes are available once Eizen joins the Party and Dire Foes appear upon completing a battle.
This Achievement is awarded for defeating the Dire Foe Bacturnian Man who will appear in Tranquil Woods, Perniya Cliffside Path, Baird Marsh, and Morgana Woods.
To increase your chances of spawning a Dire Foe:
1) Increase your Grade Gauge to 2.0
2) Use Dangerous Encounters when battling Enemies.
*Dangerous Encounters are done when two or more wandering enemies are close together and a big black shadow appears underneath them