But to the back to my point from the main feature of the game I think leaving somekind of suspense on whenever its good or not to use the power to be left a mystery is a good thing. Like I have pointed out before you could never use the tadpole then it grows anywways if you decided to drink Omeluum's potion..drinking the potion is not exactly evil temptation nor is it good. You get the ring of psionic protection in exchange.. I am curious how important that ring might be later for either path.
I disagree that it's a mystery as our characters are kidnapped by monsters that eats brains in order to sustain themselves and they have infected you with a parasite that will eventually turn you into one of them. Most people who knows D&D lore will quite quickly and reasonably presume that the tadpole powers are bad. But to your next point, I think the ring simply prevents you from being controlled by true souls and stops you from using the tadpole.
And yet every single person you meet that tries to help you remove it tells you there is something weird with your tadpole that you should already showing symptoms..netherese magic,the thing is in stasis ect. True each time you use it its like the stasis is undone for the use.. like its frozen in time unless used all at the same awhile giving you some powers....we also know the tadpole is not the only thing fighting for control in your head.. You both the the dream AND the presence in the dream telling you to kill the dream apparition... wich you can either give into one or the other or neither... once a player has all of those information I can see alot of path's branching from stopping to use it entirely or trying to follow either path in your mind. But for any of that decision making to happen your gonna either have to use it OR wait to find someone knowledgeable enough to tell you what the heck is going on.
Also weirdly enough I don't know if its a bug but several usage of the tadpole does not seem to progress the dreams. Such as trying to read SH's mind when you tell her " You know this could be our last night togheter" or trying to mind control Droz Raxin to ask the wrong questions in the goblin camp...tho checks have the particularity to have DC's above 0 so thats an interesting tid bit to add to the pile of mysteries.
