Juicing Up

I've conceived a task befitting of your "talents". Have you heard of the House of Plague? Crafters of toxins and potions. They suffered a tragic accident--a true, true shame. Herein lies the problem: I have long used the work of the plague devisers to bolster my arena performance. Without a potion of their creation, I'd find the fight unnecessarily taxing. The brokers do have such potions, but they "do not like my face." Could you obtain such a potion for me?