To go through my reasoning in more detail.
At the moment, there are, I think, three main things you might hope to get out of the Ethel quest, setting aside a tadpole cure, which gets dealt with separately: (1) save Mayrina, (2) an attribute increase, (3) kill Ethel (which gives you her loot, and enables you to save three - iirc - of her other current victims and make sure there won’t be any future ones).
As it currently stands, if you want the attribute point but don’t care about the others, then you have no real reason not to try to deceive/intimidate Ethel, as you might get to save Mayrina as well, but if it doesn’t work you can always just let Ethel go with Mayrina and get your attribute increase anyway.
Similarly, if all you really want is to save Mayrina, then you may as well try to deceive/intimidate Ethel as you might get an attribute point as well, but if you fail you can always kill Ethel.
But, if your priority is killing Ethel, you do have reason *not* to try to coerce her. Sure, there’s a high chance of failing and you’ll probably have to kill her anyway, but you could do that already and there’s a small chance you’ll win and then NOT get the main thing you want. You actually don’t want to succeed this check.
Just adding the ability to kill Ethel with 100% certainty after coercing her unbalances this, because then someone who wants to kill Ethel *also* has no reason not to give the deception/intimidation check a go, as they’ll still be able to get what they most want whether they succeed or fail, and may get an attribute increase as well. And if they succeed in this case, they get ALL THREE of the things you might want to achieve, which isn’t currently possible.
Tweaking it so that if you succeed in the check you might then fail to kill the hag would reintroduce a disincentive to Ethel-slayers to undertake the check, but it would probably just as much be an incentive to them (us!) to save-spam to get the outcome they want.
I think it’s reasonable for the game to make it (or keep it) so we can achieve a maximum of two out of the three possible objectives, and force us to choose. But there are other ways of tweaking the encounter, as we have discussed, that might also work to enable the higher reward but balance it by also increasing the chance of coming away with less, at least if we ignore saving/reloading.
