Vex Ability (LoL): Doom 'n Gloom

Every 25-16 seconds (depending on level) Vex becomes afflicted with Doom, causing her next basic ability to interrupt dashes and fear enemies for 0.75 / 1 / 1.25 / 1.5 seconds (depending on level).

Whenever a nearby enemy dashes or blinks, Vex marks them with Gloom for 6 seconds. Vex's next attack against a gloomed enemy deals an additional 40-150 (+25% of ability power) magic damage and reduces this ability's cooldown by 25%.