User blog comment:Nearthel/Critical Strike and Penetrations overhaul/@comment-5266525-20150620182331/@comment-1330314-20150621045302

new passive works for her because it prevents her from bursting enemies -- she has so much crowd control, including hard crowd control, that any situation where she'd have enough burst to kill you while CCing you would feel tremendously unfair, so her passive avoids that by pacing out her DPS as smoothly as possible. Most other champions who typically itemize for crit aren't as problematic when they do end up with burst, so that sort of passive wouldn't be the best universal fit, imo.

I like the idea of modifiers a lot. I'm not familiar with Smite, though I'm not entirely a fan of attacks just naturally scaling with AP on many different champions, since it dilutes the meaning of both AP and AD (AD is meant to be an autoattack-oriented stat which sometimes factors into abilities, and AP is an ability-oriented stat which, on rare occasions, empowers autoattacks, and both lead to different gameplay patterns). I think a simple idea to test would be that of Gypsylord's patented three-auto mechanic, where you could land a guaranteed crit against any target you'd auto three times in a row and in quick succession, with the damage increasing with crit and certain champions interacting with it in different ways (as you mentioned, champions like Caitlyn and Vayne could alter that paradigm a little by making Cait's crit mechanic or making  Vayne's way of expressing her crit power, for example).