You can compare dragons, of course, it all depends on their numbers.
To be honest, I still can't remember who I killed Nicholas with. Elves or Necromancers? It all ended so quickly... Should I replay it...?

During our first encounter, my Necromancer had about 200 dragons. He could have handled Nicholas as well. I don't remember how many Emerald Dragons Faidaen had. I played for a long time – I wanted to level up Faidaen better. That's why I left the Phoenixes in the city. However, there's not much point in leveling up a hero to level 30. It requires a lot of experience. I only got him to level 31. I got tired of it. And I was also afraid of a baby boom among Nicholas's dragons. So, I visited the level-up shrines and finally destroyed the Greater Vampire. Faidaen and the Necromancer exchanged units a couple of times – dragons for Dryads. I killed Nicholas several times.