You have to defeat soltrius in order to proceed to the next room and defeat the king of alstora, to get back to your original world.

You had died 228th times under soltrius's hands, who stands undefeated.

The second you enter inside the soltrius's room, his back is facing towards you as he knows you had arrived once again.

"You again?" His charming voice fills through the room as soltrius draws out his rapier, turning around, unamused. "How many times has it been..?"