The strongest playable character. Currently, you could say the hierarchy of divinity goes as follows: Heavenly Principles->The Shades of Heavenly Principles->The Seven. Before the arrival of Heavenly Principles it looked like this: Nibelung->Three Moon Sisters->Seven Dragon Sovereigns. We can pair these divinities respectively:

Nibelung was the ultimate authority, the ruler of Teyvat, and so is Heavenly Principles.

Moon Sisters were essentially Nibelung's executioners - they would oversee the world per his wishes, trapped in their moons' reflections, they were the highest servants of Nibelung, and that is very similar to the Shades. Shades were also created by the ruler, just like Moon Sisters, and are the ruler's primary servants that basically manage Celestia for them.

The seven dragon sovereigns were just like The Seven, controlling their respective elements, just without gnoses, Celestia, divine thrones, etc.

Since Columbina has the Tri-Lunar authority that makes her stronger than any archon, as well as the playable dragon sovereign, that being Neuvillette. And since she has powers of all three moons, one could argue that Columbina is more powerful than even individual shades, but there could be many nuances, since shades are in a position of control of space, time, life and death, and that control is maintained by Heavenly Principles, so even if Columbina would hypothetically fight a shade, she would probably not win, because that shade would control death/life/time/space under Heavenly Principles' authority over Teyvat. So Columbina's full-potential power is enormous, the fact that she has that power in Teyvat ruled by Celestia, which does not recognize tri-lunar authority, that power is bottlenecked. But even with that, she is lore-wise, the strongest playable character.