Heroes-4 "Deep forest" off-line Tournaments!

I didn't quite get how to get 324!!! mana??
From leprechauns??? But you can drain much less mana from them, even considering that they split into 4 squads!

And you forgot that ZveroBoy can pull the grave using space. And on this map, you can manage without it. Attack with a hero near the city gates, build up mana, and die. Resurrect the hero, and so on. In my Walkthrough, I got 100 mana.

Added after 5 minutes

In the first case, immediately after building up mana, you need to start building Vampires and play with their support, and for Vampire Strike, use a monk and then retreat to the Fortress.

I don't quite understand you. If after building vampires you THEN retreat again to the Fortress for Vampire Strike, can we forget about boarding the boat on day 6-7? Is that it?