Complex sentence: He would return the following year to ISWA's World Congress 2016 in Novi Sad, Serbia to give a speech about the program to it's 1500 participants and was introduced by Game of Thrones star, Thomas Wlaschiha.
Split into simpler sentences: He would return the following year to ISWA's World Congress 2016 in Novi Sad, Serbia to give a speech about the program to it's 1500 participants. He was introduced by Game of Thrones star, Thomas Wlaschiha.