In your opinion, which hero has the most charisma in the campaign?

Markel lost because he usurped power and turned all Seven Cities of the Academy, Irollan, and half of the Griffin Empire against him, not to mention that he was also at war with demons. He couldn't possibly win! He's a fool, even though he came to power in such an unusual way.

So what? The main thing is that the queen believed him, which allowed him to put his plan into action.

The queen, who couldn't hold onto her power. The queen, who stopped caring about the world's problems and believed some charlatan. As Caldwell said: "She got mixed up with necromancers, turned the empire into ruins..." The entire empire, from Archbishop Randall to the last peasant in the most remote village, hated her while she was on the throne. And Markel didn't see this.

So this Kha-Beleth, who spent his entire life sitting in a prison...

And if someone is locked up with all kinds of magical seals, giving up his flesh and using all his power. The entire life of the Master was dedicated to creating a grand plan for his own liberation. And it must be admitted that the plan was brilliant. Kha-Beleth took everything into account, except for Arantir. From his prison, he perfectly managed his task, and as a result, he turned Ashan into a pile of rubble.

...and lost on his own territory.

A small step back for a big leap forward.