I tend to avoid using both options, as they are labeled dangerous and evil. The dialog power is not that important for me, I use it very sparsely if ever. Quite often I even want fights and not avoid them. Maybe later it might be sometimes mandatory to use it, to avoid dire consequences?
The combat abilities from the tadpole are mostly too good to be true. I played a lot of classes from 1 to 4 the last time and I'm not even sure wether I always got the powers because I never tried to use them, to not get used to them.
There have to be consequences from both options, otherwise it would be a terrible lore deficiency. But, as said by others, it's difficult to find something good here. My thoughts are, if you use it up to 9 times, you have 1 hp less, if you use it 10 times or more, the Absolute takes full controll over your main char for the whole last boss fight. Maybe that should be balanced a bit better yet ...
