On-Crit Toggles
Random idea I had.
Basically, each major Crit item gets a unique toggle. Toggling one on turns off all other Crit toggles. Each toggle would give a different Crit effect granting various neat OnCrit effects. Infinity Edge, for example, would get the 'Crits do 250% damage' toggle. Other crit items would do other things.
Bleed/Grievous wounds on a new Executioner's Calling? Shiv granting double OnHit procs when it crits? Stacking IAS/Crit bonus on Dancer? Maybe a massive %armor pen effect on some new item? So on and so forth. Just spice up crit itemization a little more so it's less about giant stat-sticks and more about 'what do I need right now against this target?'
Not sure how it would interact with Ashe's new passive. Possibly just treat that thing as a Crit Toggle itself?