Oh, well now I am just annoyed that it lets you stack them, and the fact that it's a useless item taking another spot in the inventory. More so the wasted space than anything else.
Unless of course I am missing some clever use for them.
http://xseedgames.tumblr.com/post/106257618835/brandish-the-dark-revenant-localization-blog-3
- Killing That Which Cannot Die
As you progress through the game, youll encounter undead foes enemies who will collapse before you, but then rise again after only a short while has passed. There is a way, however, to keep them down for good! During your travels, youll amass a hefty stock of life-giving H.Potions and magic-restoring M.Potions but youll also amass identical-looking H.Poisons and M.Poisons, which reduce your life or magic points when consumed. These items are seemingly useless, existing solely to trick you except that M.Poison can also be used as undead bane! Simply drop an M.Poison bottle on the body of a recently-slain undead foe, and as long as that M.Poison remains undisturbed, that particular enemy will never bother you again.