I PRESUME YOU ALREADY GOT THE OK FROM MONICA FOR THIS, if Monica is okay with it, then that's chillax.

I HAD A SIMILAR ABILITY!! I wrote mine up like so if you needed any other suggestions:

◆ It does not work on people who really know him well (like people he grew up with, his own blood family, etc, it will fail everytime and they'll know he attempted to put a spell on them).

◆ If they know him decently well prior, such as a Siren's member, it's a 50/50 shot if they remember because they'll likely be able to remember his mannerisms (other person can coinflip).

◆ Doesn't matter if its a Siren's member or a complete stranger, the more he repeats this blessing on them, the higher the odds of them remembering his face and once they do, they'll remember it was him for every other instance prior.

◆ If he doesn't know the person well, he will never remember their face. Even as he gets to know them better, he'll have to solely rely on their voice or other features. Even if they remember that it was him who placed the spell on them, he won't ever be able to remember their face. Basically, permanent prosopagnosia.

I think your list is similar enough to this minus the permanent prosopagnosia, if you wanted to add that, that's fine, BUT AS IS, YOUR CURRENT LIST IS PROBABLY OKAY. I'd say for Hex, since he's not the one with the blessing, he shouldn't have anything too permanent attached, but I'll let Monica decide on what they find most fun!!