[Snake]

I believe both curses need to be exhausted first before becoming eligible to be transferred. The problem with it being moved around by only damage is... You'll always be damaging your opponent, be it directly with attacks, or indirectly with stat damage or field effect damage. There's no real way to avoid a Hexer's curse.

And even when the Hexer is cursed to shit, knowing you won't try to attack them, they'll start spamming their Invocations to further weight the combat in their favor to the point it's best to just flee, just due to how unfun it becomes to try and face them.

Making the Hexer need to 'miss three basic hits' before Fellel's Fumble can be passed, or 'be hit three times by basic hits' before Plisfa's Masochism is passed, may make it equally fair for both sides. There will be a turn where the Hexer will suffer, then the opponent follows after.

Of course, some "cheaty" methods of ignoring this through potions will also need to be negated, as Jupiter said.