User blog comment:Typhron/Flushing Custom Champion ideas/@comment-7709681-20141110233822/@comment-60764-20141112172315

The armor penetration is flat, not a %, and the penalty of such is 10% less total AD. I originally thought of adding a flat -10 AD as a penalty, but that didn't seem to be a good enough penalty.

Frost Shots is probably the most changed of the ammo types, originally an idea repurposed (ironically not from Ashe's passive, but rather Brand's), which ultimately became the odd man out due to the allocation of types/passives available. Originally there was a fire type called "Incendiary charges" that had the health% damage acidic ammo had, while AA was just armor penetration. Likewise, Frost shots were just a stacking slow that would stun for a second (with Q and R autostunning) and then giving a forbearance period while Lightning Rounds would do additional damage and reveal the target for a few seconds. Ultimately, though, I decided to consolidate effects and have a "normal" type of ammo for those who didn't want to bother with such nonsense. I couldn't quite figure out how to make fire work as a bullet type (shoots mamga or pure fire? Or just heated rounds? Where's the fun in that) so I opted to go the frost route.

To that end, I could tweak Frost shots a little, for posterity. Such as removing the slow and adding something like "prevents a % of cooldown reduction from working)", which could either scale with level or item tier. And either way, I'd have to tweak the weakness. There's also changing the effect of/switching the effects of Lighting Rounds with Frost and giving Lightning a new passive.