The Diminisher is an elite skill design for the Goliath. Not only does it give your ship a completely new look, but it also lets you weaken your enemy's shield with the "Weaken Shield Ability" in which your enemy's will take 50% more damage (Note that this ability can be countered with EMP-01). The damage distribution will remain the same but you can reach their hull much quicker with this design. The after effect will consist of a 30% reduction of YOUR shield strength. Along with that, you dish out an extra 5% more damage to enemy ships.
This design doesn't just change the look of your Goliath Battlecruiser. Use its "Weaken Shield" ability to increase damage to enemy shields by 50%, though your shield's strength will be reduced by 30% once the effect wears off. Not only that, but you'll also do an extra 5% damage.
For more information, please visit the Skill Design page