Buffs your damage and defense against a mob after killing a number of them.

For example, killing 25 total amount of Zombies increases the player's damage and defense against all Zombies, but not variants like Husks, by 5%.
The mod also increases Looting level, but the milestone for increasing the level is, by default, higher (100 kills).
Killing milestone for buffs, Damage and Defense buff percentages, and looting are configurable.
Mobs owned by the player, like pets, kills can also increase the player's tally. This can also be disabled through the mod's config.