"Sparking", you say? Original uses tenjou (literally "ceiling", or contextually "hitting the upper limit"), basically the term used by gacha players for rolling until pity. "Spark" is the term used by EN players of Cygames gacha or some equivalent points-based guarantee system that lets you "select" your pity roll.

Descending like a spark from heaven for the poor pitiable souls... wouldn't that be a perfectly fitting entrance for a saintess!?

Please, by all means, let's go with that!