Seal broken Blessings?

[PokeCosmo]

Greetings.
I have a question about Blessings (seal broken)

Often I hear, "Buying> Blessing of Twilight, seal broken for 50g" on world chat. Or some other blessings.

I was wondering, what does the broken sealed blessing do? And how do people sell it? To my understanding, blessings can bought for a few hours by having charm. Does the blessing with its seal broken have any difference?

[speeds16]

Seal Broken blessings are casted upon someone (it's likely some people abuse this for scamming so be aware) like any other skill is casted onto a mob.
Unlike the blessing-shops you see set up around usually L1 Starglade, Broken Seal blessing can't be set up like a shop.