MonsterEnvy
Legend
From my perspective there are a lot of misconceptions about the big T. When I did my research for a 5e update of Tharizdun I only found one official stat block and he as a low level god (low end intermediate if I remember correctly). Just because a god is on a course to bring out the destruction of the universe doesn't mean they are, themselves, particularly powerful on an individual combat basis. Though his only official stats had him similar in power to Tiamat (who has been stated in every edition I believe), I too doubt he will be stated.
Yeah he only has the power of an intermediate god because he is trapped.
I also am 99% sure he is not going to be in the book. Maybe a mention but I doubt even that.