Suggestion: Armor Piercing as spell?

[occasionalplayer]

Has that ever been suggested? Would that not add some interesting flavor? 
There used to be Eldritch Weapon, and I understand the reasons for its removal - but maybe proper armor piercing in a higher tier?

[Seravy]

We had no unused spell or unit enchantment slot for CoM I so it wasn't an option to even consider.

Armor piercing is basically eldritch weapon except slightly better. Instead of reducing defense by 1/3 it reduces by 1/2. But all the same issues still apply to it :
-In the early game there is nothing with enough armor to be really worth using it against
-Later on you can kill the things with high armor using Lighting Bolt, Doom Bolt, or any other spell that ignores armor which Chaos is excellent at and those are available everywhere so you don't need to be able to actually guarantee your unit will manage to hit a high armor target.
-If you buff a low damage output unit then it's still a low damage output unit. It wasn't a worthy investment. It still loses to stronger targets just doesn't go down without dealing a bit of damage in return.
-If you buff a high damage output unit then...you were already dealing enough damage and it's useless, unless you are attacking a super high armorer enemy. But super high armor enemies are not found often and they won't come early so spells are more than enough to do that.
-Finally, Armor Piercing or better is naturally available in many sources and if you have access to any of those (illusion summons, pikemen, paladins, illusion or armor piercing champions, items with Doom, Lightning, or Phantasmal) it's also useless.

So as long as it's a Chaos (or Sorcery) spell, it's just plain useless and in other realms it doesn't belong and 2 out of 5 realms ignoring defense is the perfect amount.

That said, CoM II will make it possible to add spells without having to reuse existing slots. While Armor Piercing would be still not worth adding, other unit buffs for Chaos might be - although Chaos isn't really a realm about buffing, but it does have some other unique effects you can't add to units yet like Lightning Breath, Doom Gaze, etc. many of which do pierce armor.
But redesigning the spell system for CoM II is for a later milestone. First the game needs to actually work and the things already in the brainstorming thread need to be added to it.