There are basically two ways damage is calculated from weapons.
There is the damage increase, which is usually applied as a fraction of weapon damage, and then there are damage modifiers which act on the total damage after the damage increases have been applied.
So theres Damage Increase, and Damage Modifier.
The damage % on your weapon is a damage increase type. So a 50% Damage increase weapon or 50% damage increase on your items, adds an additional 50% of your weapon damage to your base damage.
So if you were using a kryss with base damage 11-13 and factored in all your strength, tactics and anatomy and were hitting for 20-25 and you added 50% Damage increase to the kryss or equipped 50% damage increase worth of items, your damage would increase by 50% of the 11 -13 which is about 6 points giving you a total of 26-31.
Your total damage increase limit from items in this case would be 100% or an additional 11-13 points.
Divine Fury is like equipping items with damage increase on them.
Consecrate and Enemy of One, are damage modifier effects, ( similar to slayers) which take the final damage, and multiply it.
So if your weapon was 11-13 and your damage after factoring strength, tatics and anatomy was 20-25, and you cast enemy of one at 50%, you would be getting a damage out of 1.5 * the 20-25 which is 30-37.
120 Chivalry with these changes using consecrate, divine fury, and enemy of one provides 79% ( 1.79x) damage modifier and a
20% base damage increase.
Chivalry as in production provides 50% (1.5x) damage modifier damage from enemy of one, and 10% base damage increase from divine fury.
I hope that clarifies it some.