The Spoiled Strike mod increases damage by 25% per rank while reducing attack speed by -5% per rank of melee attacks for a maximum of 100% damage and -20% attack speed at rank 3.
Reduction in attack speed can be countered by Fury. With a max of each mod, it will result in 100% more damage and 10% faster attack speed. Quickening can also be added to completely negate the attack speed reduction with its 20% attack speed bonus, though with penalties to Channeling Efficiency. Can be further countered with Berserker, but only recommended on melee weapons with a decent (10% or higher) critical chance.
Stacks with Pressure Point for 220% regular attack damage.