Sorry, but i love deathwish and feel i need to be its advocate here, because it's not horrible at all.
First, there are enough deathwish units to warrant multiple playstyles. And some of them are quite good. Specially against Poison.
The easiest matches against NG poison i have are generally with my DW decks. Plague Maiden is amazing and luckily you can do well against everyone - if you're against NG, they have locks, Sweers, Yen Invo, so its best to immediately trigger Plague Maiden as they never have row removal. On the other hand, other factions like ST or SK have row removal, but rarely have locks or banishes (only the occasional Korathi) so its safer to trigger the rats on the turn you'll boost them with Morvudd/Yen/ Bone Talisman.
Another amazing DW cards are Succubus and Manticore (and Caranthir), because they fell out of play, most players dont play around them and you can counter so many valuable units with them. Yes good players will try to play around them, but if they're playing a deck which relies mostly on single units like NR Engines or NG, they have no way of doing that.
I've been able to win against NG, ST Harmony, NR Uprising, SK Lippy, SY, all with MO Deathwish.