Dota 2 is the greatest game of all time. Not video game, but game. Take video games, chess and board games, sports, all of it. Dota 2 is insane and simply the best. The sheer amount of mind energy that people can throw into the matches is unreal and the skill ceiling is seemingly endless.
If I had to make a sequel it would just be the same thing in a new engine with modern graphics to the time. I think dota 2 still has plenty of life and dont think we need a 3 yet. I think deadlock is the perfect option for something similar but with a new feeling to it.