Hmm, how about another conjuration instead that breaks only some of the nonliving issues? (Of course, the values are adjustable for balance purposes, it's the concept I'm shooting for here.)
Acidic Infusion
Conjuration, Epic, Zone Exclusive
Cost 7 Armour 2 Life 8
All Creatures lose and cannot gain Poison Immunity. Bleed loses the condition "Bleed can only affect living non-plant creatures".
But what is the thematic justification? Note that you are making the following creatures vulnerable to poison:
- Iron Golems and Earth Elementals (maybe a little plausible, but still not much)
- incorporeal creatures (no way. ever.)
Also, be careful with the wording of the bleed condition; as it currently stands you are allowing anything (including conjurations) to bleed. A bleeding mana crystal or barracks is a little odd. In general, I would be cautious when designing cards that change the definitions of traits and conditions.
Basically, we have to consider theme when making cards, or we will have the "I can't water my plants" problem all over again (which I believe could have been avoided with some initial thematic consideration - there is no good thematic reason why plants should be any less vulnerable to water than creatures, much less immune. Lightning vulnerability for things like the iron golem and the steel wall also bothers me - as a conductor, metal should be less vulnerable to being damaged by electricity, not more. People don't generally complain about this inconsistency, though)
The challenge here is to make bleed and poison more effective against nonliving creatures, right? Here are my proposals:
This is building off your acidic infusion idea, which I believe is intended to suggest that poison becomes acidic. It does this by changing poison into acid. I don't think it causes any weird thematic inconsistencies..
As for bleeding, the easiest way to do that is a rule change that you can forgo a bleed marker to give the attack piercing +1 instead. This requires no card erratas, makes bleed more useful, still gives some nonliving creatures an advantage, and I don't think it causes any thematic inconsistencies. Note that this is still irrelevant for many creatures, such as spirits, zombies, and armor 0 skeletons.