You have the power to single out an individual and subject them to a consistent influx of good luck, its intensity increasing with time. The target will experience minor bouts of fortune, such as finding money or avoiding minor accidents, which eventually escalate to major strokes of luck, such as winning a lottery or surviving a life-threatening situation unscathed. The luck chain doesn't end there though as each stroke of fortune attracts more good luck, increasing the probability of prosperous events in the future, similar to a snowball effect.
With practice, you could learn to control the level of the Blessing's effects, dictating how much of the luck should go to the victim or those around them. You could choose to spread it out like a contagious aura, imbuing the surroundings with good luck, or concentrate it on a particular individual or object for prolonged periods.
The power is always active and cannot be revoked, but you could retarget the target often to prevent the effect from reaching its maximum potential, ensuring more consistent returns of good luck. Other forms of protection or similar forms of luck powers could delay the luck's potency, but ultimately the Blessing's luck chain would overpower them, allowing the target to continue their streak of good fortune.