What if Randuin's active removed Crit Chance for a few seconds?
Instead of lowering the damage taken or slowing, it would be cool if it stripped enemies of Critical Strike Chance for a few seconds to give you and your allies a window to deal with fed enemies.
The only problems would be Yasuo and Tryndamere :/ Alternatively, it could reduce Critical Strike damage to like 50% instead of 100% for the duration.
Edit: OR the pulse could be much larger and create like a 0% Crit Chance field.
, they would lose 20% CDR too, since they would lose crit. That's cool and all, but I think it would stupid hard to balance.
Good Thing There Are no Items
That negate ''massive amounts of Gold'' from people's itemsets, right? 
that has abilities
that we wait until
we want
to re-engage
on
am I
right? 
) that's pretty underwhelming currently because the -10% is just nullified by the easy access to Armor Pen. It also makes sense because it feels fair for ADCs to not want to target the tanks instantly and makes them strategize rather then rightclick and kite; They can still do that, but now they have to worry about the tank closing gaps. runes and the like, and the fact that, lets acknowledge it, there aren't any Critical damage reduction runes, but there's critical strike runes? Yeah, giving it an active that can make a character who normally buys randiuns the ability to charge in for their team and tank a ton of shots, like
, who sees barely any play and would experience a fresh breath of air to his kit. It would also help CC tanks who don't have quick dashes on limited target-ability get in without losing half of their HP to Vayne and Jhin poke, or Ashe crits, or Twitch ults.

and
. I know that those aren't on the same scale, but they do the same thing pretty much.
since the active isn't considering armor for the damage reflection.
did on release.

Merc treads especially important to reduce all that reducible cc ;P
Just to give some examples. It got even mentioned that they are thinking about adding a crit mechanic for a champ, who is struggling alot the last time:
