Alice XV/Paradox

Alice the 15th is a returning character from the original trilogy. She should be dead, but after the disappearance of the 16th, she has seemingly returned from the grave.

Biography
After the disappearance of the 16th, three new factions arose in its wake, all with the intention of claiming the throne for themselves. Alice the 8th, Alice the 15th, and Alice the 17th.

She is brought up for the first time by the chief elf in Enrika.

The 15th took control of the 16ths army after her disappearance including her own previous supporters, thus she has the largest army, but perhaps not the most powerful individually. However, she is said to be leading the Lilith Sisters, a trio of succubi who are extraordinarily powerful.

She is brought up again after Luka beats Astaroth in Luddite Village by Astaroth.

"Alipheese the 16th... you wouldn't understand. That is why your mother removed you from the plan." In the same scene, it is confirmed the trio are the firsts subordinates, "Well then, let's meet again. I hope that you, too, work your best for our Mistress, Alice's sake..." Mistress Alice is confirmed to be the first by Ilias, "She said "Mistress Alice"... that's Dark Goddess Alice's... "

This heavily implies that the 1st resurrected the 15th. Because it certainly wasn't by Ilias. As for why the 1st did resurrect her, it cannot be said.