I’m playing an Aura of Decay poison Lich and I realized that the Poison Penetration from the Three Plagues node was applying to the poisons I inflicted on myself*, making survival very difficult at early-mid levels (35-50). I have been told this is intended behavior by Mike H via Discord but to make a post here anyways. It is my opinion that this node’s behavior should be changed, I already feel like I am lacking the tools for survival with Aura of Decay Lich as it is and now that I realize the harm that this node is doing to my survivability I feel forced to deallocate what is probably the best damage node available to me. If this behavior is not changed I think it should at least be clarified via its reminder text that it comes with a drawback to the player.
*I tested this by using Icarian Poison on Aura of Decay and timing how long it took to die to my own poisons with and without 8/8 Three Plagues nodes allocated, everything else equal.