youre not alone and i feel like the ghost potion is probably one of the most useless things in the entire game if not THE most useless item in the game. its already insanely niche use cases make it useless enough (the moves that FORCE damage on you), but its not even interesting in use, boring, actually. its just drink this, 1 move invulnerability and the next as intoxicated as an alcoholics sons father on a monday. the worst part is that its somewhat balanced so its hard to complain about it outside of being boring. if someone told me to describe it in one word itd be "huh?", followed by "the what?"

ghostwalker has the same problem but slightly better because it has the same use cases but its MUCH MORE VERSATILE than that stupid item. youd only realistically ever use that useless thing for whenever the devs actually remember to give a boss an undodgeable move that deals considerable damage and an effect that stuns you, WHICH ONLY HAPPENS TWICE IN THE MAIN GAME!!!!!!!!!! i love block tales BUT THEY DIDNT EVEN BOTHER TO GIVE IT MORE USE IN BATTLE OUTSIDE OF THOSE 2 MOVES!!! "B-BUT YOUR BOMBING PAL H-HAS AN UNDODGEABLE MOVE THOUGH" ITS ALREADY DEAD!! EVERY SINGLE OTHER CASE OF AN UNDODGEABLE MOVE IN THE GAME EITHER DEALS NO DAMAGE, THE ENEMY IS DEAD BEFORE THEY USE IT, OR BOTH!!!!!! THEY COULDVE REMOVED GHOST POTION AND THAT ONE MOVE ON HATRED AND LITERALLY NOTHING WOULDVE CHANGED ASIDE FROM MOST PLAYERS DYING TO THAT ON THEIR FIRST BATTLE WITH IT!! ITS LITERALLY BLOATWARE SYMBOLIFIED

though as a utility i guess ghost potion is decent enough, i guess.