purify only does hp poison.. sanctuary heals 4 and prevents your hand from being messed with.. only nightmare and ghost of past and discord are affected..
healing pod has a bigger purify, and removes all poison from all creatures on your side. this completely stops alfatoxin, vampire, virus, retro virus, deadly poison, arsenic and anything else that would make otyugh weaker with eating poisoning monsters.
I figure with all the cards it does stop compared to the other 2 cards the cost is fine.. i could maybe drop it down to 6-8 and drain all.. mainly the point of the high cost was to keep from using 6. i run 1 purify and 1 sanctuary.. more or less they are nothing but a +1 or +4 healing.. plus 1 of these.. +3 healing and if i have poisoned creatures. its in the armory so its up to Zanz now for using this or a card similar in effect. i can only hope.