It is true Season 2 is going to premeire on June 24, 2018!!! But I want to metion that Stalyan is not the only new character according from a exclusive post there are serveal other characters that you will see in Season 2, the other new characters are: Madam Canardist , Goodberry, King Edmund, Vex, and Seraphina. Demanitus (he is the person who created an important device used in Queen for a Day and he was a hero that is metioned in one of Xavier 's legends) will make his first apperance in Season 2.
I doubt if we will see Goodberry the fast-talking host since the season is about Rapunzel uncovering the mystery of the black rocks and also about Eugene 's past but Goodberry could be a minor character. And I wonder what Seraphina looks like I mean they said she's beautiful but that is not enough detail. I also want to know is Madam Canardist the mysterious warrior or not, and who exactly is Vex. I don't know King Edmund ethier but we will find out soon. I also hope Quirin get freed so he will talk some sense into Varian to make him good again and I really hope that Quirin will finally reveal his secret to us and maybe to Varian as well.