Heroes 5.5 WarGame Edition - Tactical Edition.

"...The most powerful of liches receive a special blessing from the Spider Goddess. They die and are reborn, becoming "Ahharus," or vampires. Vampires do not need food or water, do not sleep, and do not breathe. The Goddess's poison flows in their veins. But in order for this poison not to destroy their body from within, they need to regularly drink human blood.

I don't like the lore of Ashan, starting with the 6th installment. The visuals were changed and spoiled, and the logic was also altered in places. For the most part, I rely on the visuals of the 5th installment + classic fantasy.

especially annoying are the witch in the 6th, the hydra in the 5th, the bear in the 3rd, and the centaur in the 2nd. With the griffin in the 4th, it's still bearable.

In my opinion, a griffin cannot be weaker than a Knight, because horses are prey for griffins. In WGE, griffins are tier 5, and knights are tier 6, but this is just formal, and in reality, they are equal in strength. Moreover, griffins are equal not to ordinary ones, but to elite cavalry, on elite super-heavy horses. That is, it is necessary to bring the Knights up to the level of griffins, and not vice versa.
In the 3rd installment, there was complete nonsense, when some miserable swordsman, who would hardly defeat even a walking lion, was higher in tier than a griffin.