I'm having more luck with the Death Splinter than I did in the past. Sometimes, when I can get the Undead Archer to afflict and the Haunted Spider and Assassin to poison, that gives me the edge I need. It doesn't always work, but I used to hate Death Splinter and now I seem to find better luck with it.
Yes, getting poisoned is no fun :-)
I did lose a lot during the last seasons playing against the players that use those cards. Especially if I'm playing Water.