using spells and their usefulness on the map and in battle.

So, a little bit of Necropolis-themed content, but that's okay... If, let's say, troops from 4 races are gathered and the morale drops by minus two, then if you use Mass Joy, how much will it improve the morale and reduce the chance of negative morale occurring? Or, for example, in a game against an enemy hero with leadership or simply high morale, how much will casting Mass Sadness reduce the chance of morale drops and prevent an extra turn? Added 1 minute ago.

JustObserver used an Assassin in Utopian, and it worked well against Coronius.

And how effective is it compared to, say, speeding up someone, blessing, or other spells? Added 8 minutes ago. And also, can Mass Misfortune reduce the high luck stats of an enemy army and prevent luck from occurring, and how effective is it?