Which hero is better to choose?

You should have taken the time to read this thread more carefully: /topic/2049/, and also other threads in the Tactics section (instead of creating a new empty thread – /topic/4903/). You would find answers to many questions there. After all, you can't give a definitive answer to your question – like, take this hero, and you will immediately become a champion. Much depends on personal preferences, and advice may be diametrically opposed. Study the theory, use your brain, and then ask more specific questions. For example, in the Physics and Mathematics Institute forum (/topic/421/), there is a section on Necropolis strategies and tactics.