I haven't seen that anime, I definitely should check it out. I was into DOTA briefly when it first came out and kinda dropped out when it became hyper competitive and toxic.
Dragonheart. I said elsewhere that I love that one, but am not quite so enthusiastic for any of the sequels. They just didn't do the original justice.
I'm working on finishing GoT before I watch this.
I have to say that Viserion is one of my favorite dragons on screen. I've always loved the D&D Dracolich concept, and that's the closest we've gotten in a show more movie.