Known sins are:
...Breaking a Covenant pledge.
Safely abandons the player's current covenant free of cost and without committing a sin.
List of possible Sins
...Break a Covenant. Either by making NPCs of said covenant hostile or joining another covenant without properly abandoning said covenant thru Oswald.
But I believe this is false, and using the Abandon Covenant option has nothing to do with preventing sin. Can anyone point out a specific example where breaking covenant is a sin? I think the confusion comes from:
1) Having the option to abandon covenant through Oswald (making people think it has a purpose)
2) A few instances where getting kicked out of a covenant happens to come with a sin 'by coincidence'.
For #2, I think the distinction to make is that there are some actions that can cause you to sin and be kicked out of a covenant at the same time. But the sin acquired isn't obtained by breaking the covenant- rather, the thing that caused you to get kicked out also happened to cause sin.
That may sound like a pedantic distinction, but I think it's important to know since confusing the two has lead to what I think is an incorrect explanation.
I haven't yet tested all of the covenants, but here's what I know so far:
- Leaving the Forest Hunter Covenant for another, without using Oswald, is not a sin
- Leaving the Chaos Covenant for another, without using Oswald, is not a sin
- Leaving the Darkmoon Blade Covenant ... is not a sin
- Leaving the Princess's Guard Covenant ... is not a sin
- Leaving the Warrior of Sunlight Covenant ... is not a sin
- Leaving the Darkwraith Covenant ... is not a sin
That only leaves Gravelords, Path of the Dragon, and Way of White untested, but I highly doubt they'll be an exception.
Go to Oswald without any sin, and you'll find that you can keep switching covenants all day long and you'll never acquire sin. Attempting to request absolution will tell you that you have not sinned, nor will you obtain sin in the book of the guilty (as expected, the latter is only for indictments...).
Is there any point to using Oswald to Abandon Covenant? I think it serves no purpose, outside of possible roleplaying purposes (if you wanted to be covenantless again or something).