Talk to Nadia in the building [A] east of Seraphim Tower.
Speak with Florentina in a building [B] south of Seraphim Tower (you will be teleported near Sko's Corner, to be teleported back - you must complete the quest).
The Arena Above the Clouds
Speak with Saskya in the north-west area of the Seraphim Island [C] and you will be teleported to Seraphim Arena (you have to fight with three enemies here, in addition you will lost if you will leave the arena before the death of all enemies).
The Dragon Cult
Talk to Jarofein who is standing in the underground corridor [D].
The Third Sacrifice
Speak with Kelsior [E].