[QUESTIONS and ANSWERS] Walkthroughs for the Heroes 3: RoE, AB, and SoD campaigns.

I've reached the last Campaign, "Darkness Hunter" (I've completed all the others in SoD and Era). I have a question: what's the best way to develop the Dragon? Should I max out all types of magic, or is it better to leave one skill slot for Diplomacy? Or maybe something else? Initially, he has Wisdom, Sorcery, and Scouting... so I'm wondering what to spend the 5 free slots on. I'm thinking one slot for Earth Magic, and another for some other magic... I'm not sure. I also want to take Diplomacy... it might be useful. Logistics would also be helpful. And Intelligence would look good with Sorcery and Expert Magic. And another question: besides troops (and skills, of course), does anything else carry over to the next turn? Artifacts, etc.? This question arose because I played this Campaign a few years ago and couldn't get past the second map. The enemy kept attacking and destroying all my troops... and after that, I didn't play it anymore. Maybe I just wasn't playing well back then. I recently completed the Swamp Campaign, which I also couldn't pass before. But they say this Campaign is difficult, and some people complete it with cheats, but I don't want to use them, because I managed to complete all the others normally. I'm waiting for advice. P.S. Maybe I can complete it anyway... but it's better to be prepared