A new race: Vampires.

As for the strength of vampires in Heroes and the fantasy world, they are appropriately balanced.
A vampire is not stronger than a black knight or a lich; think about it. A black knight can be defeated by destroying his armor, and a lich is protected by magic, which a vampire cannot overcome.

I hope this closes the discussion.

A vampire is not stronger than a lich? Why is that? Vampires can also learn magic; it's just that it wasn't implemented for them in the game. Moreover, ancient vampires have immense strength and, most importantly, speed – so fast that an ordinary person or even a low-level vampire wouldn't be able to notice them moving. A lich is undead; it's not alive and can only stand (or walk, but at a normal speed) and cast curses, which, by the way, don't affect vampires.