So this is simply as the title says, add counterplay to Vi ult, like QSS the initial lockdown, have stealth do like a "soft cancel". Because let's be honest, as an adc or mid laner it's not fun getting flash vi ulted with a point and click lockdown skill, Even a vi that's feeding can get value in picks/teamfights by just pressing R on the carry while her team blows the carry up, with no counterplay.
If they take power out of her R, they'd have to put it somewhere else just because her sticking power is actually kinda weak unless the target is already slowed/trapped.
TBH, Vi's kit is pretty solid because the only reliable thing you know can do is R one person. Plus with shields, heals, GA being decent and overall team peel, Vi puts herself in as much danger after she lands too.
if you can go untargetable (read: invincible) you can cancel her ult
you can interrupt the ult. At least could at some point. Easiest would be knockups/knockback. Know for sure I canceled her ult a couple times with cho's knockup. Don't think other CCs like stuns or snares do the job though.
The counterplay is that Vi can't afford to build much damage items since she'll be too squishy, and if she can't build much damage items she won't kill the person she ults. Likewise, the person she ults has time to run away/heal/shield and force Vi into a bad position.
She drags herself towards an opponent. If that opponent flashed into a position that would be bad for Vi then Vi dies. She has to commit to every ult, that's the counter play.
Positioning.
