Мод Master of puppets v3 "Battery"

What do you mean?

MoP has a comprehensive guide to all the new features. It clearly explains what and how. Here is a small excerpt:

Marriage relations can arise between two heroes of different genders and absolutely any alignments. To do this, they must get married (meet), having two Wedding Rings (artifacts, of course).
Marriage has three bonuses that depend on the marriage level 1...5 (depending on the duration in days):
1. Receive 10-50% of the spouse's combat experience.
2. Morale: +1 ... +5.
3. Attack or Defense bonus 5-25%
The husband receives a percentage to attack, and the wife receives a percentage to defense (the wife inspires, the husband protects). At the same time, it does not matter if the hero has this skill - the bonus is simply added. It is not amplified by special abilities.

In Mourning, the bonus is inverted.
If one of the spouses dies or is even simply dismissed, the other falls into a state of Mourning, which also has its own duration, equal to the marriage level multiplied by 7 days. Mourning is characterized by a decrease in Morale - first by a value equal to the marriage level, but each week it decreases by one (the hero gradually "forgets" his spouse). Also, the Attack/Defense bonus is inverted during this period (the widower fights worse, the widow is poorly protected).