***TRIALS RESPONSE***This Death stall is very very effective in PvP and is quite annoying. Even though you said you just threw some decks together you have done a good job at building an effective stall. The Arsenic adds just enough offense to allow this deck to beat many of the decks it faces. Poisons allow the deck to bypass shields, while Viruses, Plagues, and Bone Walls take care of creatures.
One card that I might add to this deck is Soul Catcher. In these types of decks, Soul Catcher can be very valuable with all the creature deaths caused by the plauges and viruses. I would replace a few Pillars/Pends with some Soul Catchers.
Also, since you are slowly poisoning them to death, a 42 card deck isn't required to win. Slimming this deck down could help increase your chances at drawing your Arsenics or other crucial cards. One way that could make the deck size smaller is removing some of the excess cards, such as Bone Walls. Seeing as your Bone Walls will reach high numbers, 6 of them are not required to keep blocking damage. With the removal of a few Bone Walls and the rest of your cards having a playing cost of no more than 4, you can trim down on the Pillars and Pends a bit. Bringing the deck down to about 38 cards would be optimal here, so removing a few Bone Walls and Pillars as well as a few other various cards will give you this deck size.
If you have a few cards to spare, you might want to consider adding an extra Arsenic or two. An early Arsenic can make a huge difference in any game and have extra to spare in case of Steals/Deflags/Pulvys is always a good idea. With these modifications, your deck should look something like this:
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52g 52g 52g 52g 52g 52g 52i 52i 52i 52i 52i 52o 52o 52o 52o 52o 52o 52p 52p 52p 52p 52p 52p 52q 52r 52r 52r 52r 52v 52v 52v 542 542 542 542 542 71a 71a 8pk
Overall, this deck is extremely fun to play with I really like your take on this deck. Good job!