Auto-translated
;) it's simple:
Go to the advanced map editor (if you don't know how, this guide isn't for you). Then select View > Game Database > Game Database Window (it should be there, but if not, create a new one). A new window should appear under Property Window. It has two tabs, and one of them is Dialog Scene (if it's not there, no problem, select Select Tables and find the desired phrase). The other is needed to create your own arenas, but for now, the ones that are already included will be enough. So, go to Dialog Scene. For starters, you can look at the developers' dialogue scenes to understand what's what. That's what I did.
To create your own scene, right-click on the list, first create a folder (you can have several, like I do), and then click New Object. That's it. You can figure out the rest yourself. To play the video, press P; to stop it, press S.
Always specify either HeroLink or MonsterLink (but not both). It's best to immediately place a monster on the map (it doesn't matter if it will participate in the scene) and then always refer to it. Using HeroLink is much more complicated... so I don't recommend it. If you don't specify it, the editor will give an error and crash.
Here are a few more buttons:
E - create a new camera
Q and A - change the screen position relative to the Z-axis
W - shade part of the screen. This is needed to see the frame exactly as it will be displayed in the game.
9 - add animation to the actor (may cause a critical error).
Good luck. And if you have any questions, I'll always answer them:)
P.S. It's a pity, but it seems that interest in the Heroes series has waned recently:(