Unfortunately even if it passed or an item like this came to be. I don't think it would work the way you're hoping it would work. Malz minions and Zyra plants for one count as spells. Hence why morellonomicon works on both units and if both were infernal would create a zone underneath targets stuck by said minions as well as functioning as unit instead of a DOT. Things like repeating crossbow can be equipped by both as an example. They are applying DPS not a DOT to a target. Poison, Morello, Red buff would be impacted as they apply a DOT on the target.
At least that's how I see it currently. Would I like this still yes. I'd like to give my carry a way to not be affected by poison and anti-healing so easily.