Darkmoon Blade post-betrayal

Hey guys,
I didn't see the answer to this in the sticky thread about Darkmoon Blade.

I was previously a Darkmoon +1, so I got the Darkmoon Blade miracle. On my quest to platinum the game, I had to join another covenant, but wound up rejoining the Darkmoons recently. I can use Darkmoon Blade again, though I'm back to rank 0. I have been racking up souvenirs from pvp in the Kiln, but to get Knight's Honor, I'm going to have to kill Gwyndolin, as much as it pains me to do so. The question is, when I cash in my Souvenirs and rank up, is the boost to Darkmoon Blade's damage permanent, or is it contingent on my maintaining rank? If it's permanent, I may keep pvping until I get 80 and cash in, but if it isn't, I'll probably save the souvenirs for NG++.

It's based on rank, so by killing Gywndolin you'll be kicked out and unable to use it anymore.

Sorry maybe I didn't word that correctly...
I know I'll be booted from the Darkmoons, but in NG++ I'll be able to rejoin them and use DMB again. I want to know if when I rejoin (as a Darkmoon rank 0, half current, whichever it is)) what will be the status of my DMB miracle? Will it be leveled up from having reached rank 3, or will it go back to its original strength and require me to rank up again?

If you use Oswald I believe he either nulls the effect, or you only take a -2 effect from covenant level. In which case you'll know then. i'd recommend saving them and joining after.

Ooh ok I get you. Logic says it will stay rank based, I can't see it being a permanent boost if you derank. Really I'm not for sure but that makes the most sense to me.

I'd just wait before giving my souvenirs if I were you. Save your souvenirs, kill Gwyndolin, do everything else you gotta do, then rejoin in the next playthrough and give your souvenirs when you know you'll be staying.


Edit: Crescent makes a good suggestion though. According to the wiki, if you leave your covenant through Oswald, you will not have any penalty when you rejoin.