One of the spells in the Season 1.1, Tangled Skulls, introduces the game’s first stat impairment.
The spell has two components, a Wither debuff, and a chance for a 10% Power impairment.
The game, however, has a bit of trouble communicating impairment effects to players at the moment.
An example of a fully successful cast of Tangled Skulls highlights this issue.
Enemy Stats (mini-boss) before cast:
The cast lands and the game shows the Wither debuff on the opponent, but there is no signs if the Power impairment landed or not… (EDIT: there is a Power Down! text pop-in that appears for a moment when the impairment lands successfully, but there is no permanent icon that shows that the impairment is in effect.)
… so, the Player has to pull down the manual stat screen to see if the impairment landed or not. In this case, it did.
Interestingly, the Wither debuff affects the Power impairment, as Power is debuffed by 20% and not 10%. This reduction carries down and is shown in reduced Damage output by the enemy, as shown.
That said, as the Power impairment does not affect the weapon damage of the opponent, this results in a rather underwhelming outcome.
1035 / 15685 = ~6.60% auto-attack damage reduction.
On spell damage,
Net damage deduction on Harpy Screech is (13340 - 11270) = 2070 / 13340 = ~15.52%.
Better. Still weak, but not completely dismissible. The stronger impairment effect is a result of Power being a stronger component of a spell’s damage formula than it is in a weapon’s damage formula (where raw weapon damage is usually the stronger damage component).
Of course, the first stat debuff obviously is not going to break the game, as there is always going to be the need for power creep in the future. It does also open the question on if there will be weapon-dulling effects in the future (rust monsters, anyone?) and how that information would appear on the stat page (straight damage stat deduction)?