At max level the Legendary Killer Class Mod grants the following stat bonus:
Team - Crit Damage: +62%
Borderlands 2 Class Mods can boost up to 6 different skills by 4, 5 or 6 Points. A Class Mod's Bonus Point distribution depends on its rarity, level and parts.
Here are the maximum distributions at Level 50 and above:
Slayer of Terramorphous: (4/4/4/4/4)
The Skills an Armor comes with depend on the 2 Classes Powers and their order. Select the Main and Secondary Class to see the Armor's Prefix and which skills it can have.
Dedicated Drops are Class Mods that only drop from its dedicated sources.
Unlike World Drops who can drop almost everywhere at a small chance.
Loot Luck Formula
P = Dedicated Loot Pool Chance
L = Loot Luck