With Littlefinger out of the way, Varys is now Games of Thrones' most devious character. In season 6 we learned that "the Spider" had brought Dorne to Daenerys' cause, and in the final episode, he stood at Dany's side as her fleet set sail for Westeros. But looking back, it seems as though Varys has been team Dany since the very beginning.
After learning she'd survived Robert's rebellion, it was Varys and his old friend Illyrio who arranged her union with Khal Drogo, giving her part of the army she'd need to take back Westeros. Also, despite their clear mutual understanding, Varys testified against Tyrion Lannister when he was found guilty of Joffrey's murder, only to later smuggle him out of Westeros and send him to Daenerys.
In season 7, the eunuch clashed with his new queen on occasion, leading some to theorize that he'd betray her for Cersei in season 8, though the pair seemed to come to an understanding on backstabbing before the finale. He did tell Daenerys that his loyalty was to the realm, however, making it clear that he would always put the people above his ruler.
Varys has intimate knowledge of Dany's war council and could potentially turn the tide in the fight for the Iron Throne should he decide to switch sides again. Chances are Varys will keep his cards closer to his chest than ever in season 8, especially after being told by the departing Melisandre that he's going to die in Westeros.
