They were both undead Thorns, their bodies so vaguely shaped that they looked like green mannequins. Lith didn't recognize their energy signature, hence he had no idea what kind of undead they were nor what kind of abilities they possessed.
He Blinked behind their backs, cutting them in half with a single slash before setting them ablaze with the black flames of his tier five spell, Setting Sun. The undead cussed out loud, revealing themselves to be a male and a female.
They respectively unleashed a Chasing Lightning and a powerful pulse of darkness magic.
The first spell forced Lith on the defensive, while the other dispelled enough of the black flames that by sacrificing their lower halves the undead managed to escape by burrowing through the ground.